West Kensington Estate Tenants and Residents Association and another v Hammersmith and Fulham London Borough Council and another

West Kensington Estate Tenants and Residents Association and anoth-er v Hammersmith and Fulham London Borough Council and another [2013] EWHC 834 (Admin) QBD, ADMINISTRATIVE COURT Mr Justice Lindblom 9 October 2013 Judgment JUDGMENT: APPROVED BY THE COURT FOR HANDING DOWN (SUBJECT TO EDITORIAL CORREC-TIONS)                MR JUSTICE LINDBLOM:                            Introduction             1. In Earl’s Court, in west London, major development is planned. A large area of land and buildings is pro-posed for regeneration. Within it are the exhibition centre and two housing estates, the West Kensington and Gibbs Green estates. It is known now as the Earl’s Court and West Kensington Opportunity Area. The claimants in this claim for judicial review, the West Kensington Estate Tenants and Residents Association and the Gibbs Green and Dieppe Close Tenants and Residents Association, together represent about 1,700 people who live in the estates. They are opposed to any project that would involve the estates being rede-veloped. In this claim for judicial review they challenge the Earl’s Court and West Kensington Opportunity Area Joint Supplementary Planning Document (“the SPD”), which was adopted by the defendants, the Hammersmith and Fulham London Borough Council (“LBHF”) and the Council of the Royal Borough of Ken-sington and Chelsea (“RBKC”), in March 2012. They have also objected to the proposals of the first inter-ested party, EC Properties Limited, for development including the demolition of the estates and the construc-tion of new housing, as well as other uses. The second interested party, Transport for London (“TfL”), has not taken part in the proceedings. But the Mayor of London (“the Mayor”) has, on behalf of the third interest-ed party, the Greater London Authority (“the GLA”). The Mayor intends to adopt the SPD as supplementary planning guidance, but has waited for this claim to be dealt with by the court.                The issues for the court             2. The claimants issued their claim on 18 June 2012. Permission to apply for judicial review was granted on the papers by H.H.J. Sycamore, sitting as a deputy judge of the High Court, on 11 October 2012. The deputy judge was not persuaded that permission should be refused for the claimants’ delay, as had been submitted by the parties opposing the claim. He did not, however, grant permission for all five of the claimants’ grounds. He refused permission for ground 3, which alleged that LBHF and RBKC had each failed to discharge its public sector equality duty. That ground is no longer pursued. So there are now four grounds, to which I shall refer as grounds 1, 2, 4 and 5. 3. The main contentions are these: in ground 1, that the SPD ought to have been prepared as an area action plan under regulation 6 of the Town and Country Planning (Local Development) (England) Regulations 2004 (“the 2004 regulations”); in ground 2, that when LBHF and RBKC adopted the SPD they erred in their ap-proach to the provision of affordable housing and, in particular, in the use they made of a study of economic considerations, the “Estates Regeneration Economic Appraisal” (“the EREA”); in ground 4, that the SPD does not conform with the development plan in its provisions for social housing; and in ground 5, that the SPD ought to have been subject to strategic environmental assessment (“SEA”) complying fully with the re-gime for SEA, but was not.                Background             4. The Opportunity Area straddles the borough boundary, and extends to about 37 hectares: 28 hectares of the North End and Fulham Broadway wards in LBHF’s area, and about nine hectares of the Earl’s Court ward in RBKC’s. It is bounded by Warwick Road and the West London railway line to the east, West Crom-well Road (the A4) to the north, North End Road to the west, and Old Brompton Road and Lillie Road to the south. As well as the exhibition centre and the housing estates, it includes the Seagrave Road car park, to the south of Lillie Road and beside the West London line. 5. The West Kensington and Gibbs Green housing estates are to the west of the exhibition centre and TfL’s depot in Lillie Bridge Road depot. They are owned and managed by LBHF. There is some other residential development in the Opportunity Area, but most of it is in the estates. The West Kensington Estate is the larger of the two. It provides 604 homes, most of them flats. 476 of these dwellings are social rented. About 1,500 people live there. The Gibbs Green Estate provides 98 homes, of which 56 are social rented. About 200 people live there. Some of the dwellings on the estates have been bought under the “Right to Buy” scheme, but most of them – more than three quarters of the total – are social rented. LBHF has recently spent about £15 million refurbishing them, under the Decent Homes Scheme. 6. The West Kensington and Earl’s Court Opportunity Area is one of a number of Opportunity Areas desig-nated in the spatial development strategy for Greater London, the London Plan (2011). 7. LBHF and RBKC have each prepared and adopted a core strategy LBHF, the Hammersmith and Fulham Core Strategy of 2011; RBKC, the Royal Borough of Kensington and Chelsea Core Strategy of 2010. Both contain policies for the Earl’s Court and West Kensington Opportunity Area. 8. The SPD was jointly prepared by LBHF and RBKG It was published after both LBHF and RBKC had re-solved to adopt it – LBHF on 19 March 2012, and RBKC on 22 March 2012. It sets out a number of Key Prin-ciples for the regeneration of the Opportunity Area, and guidance on each. 9. On 30 March 2012 LBHF granted planning permission on an application made by EC Properties Limited for planning permission for a residential development to replace the Seagrave Road car park. On 3 Septem-ber 2012 LBHF decided to enter into a conditional land sale agreement with EC Properties Limited, in which it was agreed that the housing estates would be included in a comprehensive redevelopment in the Oppor-tunity Area. EC Properties Limited applied to both LBHF and RBKC for planning permission for the redevel-opment of a site of 28 hectares, including the estates. In LBHF’s area 5,845 new “residential units” are pro-posed, of which 589 are intended to be social rented and 676 of intermediate tenure. In RBKC’s area 930 “residential units” are proposed, of which 64 will be affordable, in intermediate tenure. Both LBHF and RBKC have resolved to grant planning permission for these proposals, LBHF on … and RBKC on … . Decision no-tices have not yet been issued because the parties are negotiating an agreement under section 106 of the Town and Country Planning Act 1990 (“the 1990 Act”).                Ground 1: the lawfulness of the SPD                            The statutory provisions             10. Section 38(2) of the Planning and Compulsory Purchase Act 2004 (“the 2004 Act”) provides that the de-velopment plan for any area in Greater London consists of the spatial development strategy, the develop-ment plan documents that have been adopted or approved for that area and any neighbourhood develop-ment plans made for it. 11. Section 15 of the 2004 Act requires local planning authorities to prepare and maintain a local develop-ment scheme, which must, among other things, specify the local development documents that are to be de-velopment plan documents. Development plan documents are subject to specific statutory procedures for their adoption, including independent examination under section 20 of the 2004 Act. 12. Section 17(3) of the 2004 Act provides that a local planning authority’s “local development documents must (taken as a whole) set out the authority’s policies (however expressed) relating to the development and use of land in their area”. Section 17(7) provides that regulations may prescribe “(za) which descriptions of documents are, or, if prepared are, to be prepared as local development documents”, and “(a) which descrip-tions of local development documents are development plan documents”. The relevant regulations at the time of the adoption of the SPD were the 2004 regulations. 13. Regulation 7 of the 2004 regulations provides that documents in three categories must be development plan documents, namely.    “(a) core strategies,    (b) area action plans, and    (c) any other document which includes a site allocation policy.” Regulation 2(1) defines a “site allocation policy” as “a policy which allocates a site for a particular use or de-velopment”. 14. Regulation 6(3) provides that a “document of the description in paragraph (1)(a) is referred to in the fol-lowing provisions of [the 2004 regulations] as a core strategy”. The description given in paragraph (1)(a) is:    “… any document containing statements of –    (i) the development and use of land which the local planning authority wish to encourage during any specified period;    (ii) objectives relating to design and access which the local planning authority wish to encour-age during any specified period;    (iii) any environmental, social and economic objectives which are relevant to the attainment of the development and use of land mentioned in paragraph (i);    (iv) the authority’s general policies in respect of the matters referred to in paragraphs (i) to (iii); ….” 15. Regulation 6(4) provides that a “document of the description in paragraph 2(a) is referred to in the fol-lowing provisions of [the 2004 regulations] as an area action plan”. Paragraph (2) contains the “descriptions of other documents prescribed for the purposes of section 17(7)(2a), which, if prepared, are LDDs”. The de-scription given in paragraph (2)(a) is:    “… any document which –    (i) relates to part of the area of the local planning authority,    (ii) identifies that area as an area of significant change or special conservation; and    (iii) contains the authority’s policies relevant to areas of significant change or special conserva-tion; …”. Paragraph (2)(b) refers to another type of document that, “if prepared”, will be a local development docu-ment, namely “any other document which includes a site allocation policy”. 16. Regulation 2(1) defines a “supplementary planning document” as “an LDD which is not a DPD …”. 17. Regulation 13 contains general provisions for the form and content of local development documents. Regulation 13(5) requires that “[where] a DPD contains a policy that is intended to supersede another policy, it must state that fact and identify the superseded policy”. Regulation 13(8) states that the “policies” in a sup-plementary planning document must be “in conformity with” the policies “in the core strategy” and “in any other DPD”. 18. The Mayor’s statutory plan-making powers were not provided in the 2004 Act, but in Part VIII of the Greater London Authority Act 1999 (“the 1999 Act”) and in the Town and Country Planning (London Spatial Development Strategy) Regulations 2000 (“the 2000 regulations”). When the Mayor produces supplementary planning guidance he does so incidentally to his planning functions under sections 30(1) and 34 of the 1999 Act. The spatial strategy for London is required to “include a statement formulating the Mayor’s strategy for spatial development in Greater London” (section 334(2)) and to “deal only with matters which are of strategic importance to Greater London” (section 334(5)). Section 334(7) provides that the spatial development strat-egy “must contain such diagrams, illustrations or other descriptive or explanatory matter relating to its con-tents as may be prescribed by regulations under section 343 …”. Regulation 5(4) of the 2000 regulations provides that “[no] key diagram or inset diagram contained in the spatial development strategy shall be on a map base”. 19. Section 24(1)(b) of the 2004 Act requires local development documents prepared by local planning au-thorities in London to be in “general conformity with” the spatial development strategy.                The London Plan             20. Policy 2.13 of the London Plan sets out the general strategy for Opportunity Areas, whose locations are shown by pentagonal symbols on Map 2.4. The policy divides into two main parts. The “Strategic” part de-scribes what the Mayor will do. The second part of the policy relates to “Planning decisions”. It makes clear what proposals for development in Opportunity Areas should do, which includes contributing “towards meet-ing (or where appropriate, exceeding) the minimum guidelines for housing and/or indicative estimates for employment capacities set out in Annex 1, …”. 21. Paragraphs 2.58 and 2.60 of the London Plan explain what Opportunity Areas are and what the Mayor expects to happen in them:    “2.58 Opportunity Areas are the capital’s major reservoir of brownfield land with significant ca-pacity to accommodate new housing, commercial and other development linked to existing or potential improvements to public transport accessibility. Typically they can accommodate at least 5,000 jobs or 2,500 new homes or a combination of the two, along with other supporting facilities and infrastructure.    …    2.60 The broad locations of London’s opportunity areas … are set out in Map 2.4. The strategic policy directions for London’s opportunity areas …, and minimum guidelines for housing and in-dicative estimates for employment capacity, are set out in Annex 1. Together, the opportunity areas have capacity for 490,300 additional jobs and 233,600 additional homes; …” . 22. Annex 1 to the London Plan says, in paragraph Al.l, that it is “integral to policy 2.13”. It explains how the “broad principles” in Policy 2.13 should be applied to the Opportunity Areas, “including indicative estimates of employment capacity and minimum guidelines for new homes to 2031”. Table A1.1 in Annex 1 describes the 33 Opportunity Areas. The Earl’s Court and West Kensington Opportunity Area is Site 8. Its area is said to be 36 hectares; its “Indicative employment capacity”, 7,000 jobs; the minimum number of new homes to be pro-vided in it, 4,000; and its Opportunity Area Planning Framework, “In Preparation”. The “Strategic policy direc-tion” given for it is this:    “The Area presents a significant opportunity for regeneration comprising estate renewal and housing and employment growth. A comprehensive approach should be taken to planning the future of the exhibition complex, the Transport for London, Lillie Bridge Road depot, the local authority housing estates and other sites in the vicinity. The potential for a strategic leisure, cultural and visitor attraction and strategically significant offices should be explored together with retail, hotels and supporting social infrastructure. The Mayor is working with the boroughs and landowners to develop a planning framework for the area. This, informed by a transport study, will determine the optimum development capacity for the area which is likely to be sig-nificantly higher than the minimum figures shown here. Earl’s Court has good public transport facilities and these should be further enhanced, together with comprehensive highway and streetscape improvements. Earl’s Court already benefits from a strong identity, distinctive townscape and a range of heritage assets, all of which should be upheld and promoted through the regeneration and growth of the area.”                The development plan documents             23. The relevant development plan documents are the two core strategies and the saved unitary develop-ment plan policies for each borough.                LBHF’s core strategy             24. The first of the “Strategic Objectives” set out in paragraph 5.1 of LBHF’s core strategy is to “encourage regeneration of the most deprived parts of the borough, especially in the White City area, North Fulham area and Hammersmith town centre area”. 25. Chapter 6 of the core strategy is entitled “Delivering the Council’s Vision”. In the first part of this chapter – “A: Planning for regeneration and growth” – the quantities of new housing and the numbers of new jobs for different parts of the borough are indicated. Paragraph 6.3 explains the figures. It goes on to say that alt-hough the core strategy “identifies the potential for estate regeneration in some cases, it does not include any site specific proposals for development within estates”, and therefore that “the figures do not include any estimates for additional housing as a result of estate regeneration.” The “Comment” for the “Indicative addi-tional homes” in the Fulham Regeneration Area says that the total number of additional homes “does not as yet include the West Kensington and Gibbs Green Estates”. Paragraph 6.6 says that some of the regenera-tion areas “include existing housing estates where there are questions over their short or long term suitability to provide decent housing and environmental standards”. It adds that there is, therefore, “a potential case for regeneration whether involving refurbishment, selective improvements; or partial or phased redevelopments”, and that “[it] is possible to consider that the scope for existing estate residents to be rehoused within the lo-cality, especially where this would enable them to achieve better housing, more suited to their needs, or en-able the most unsuitable estate accommodation to be vacated and renewed”. The text in the box beneath paragraph 6.6 refers to LBHF having “given assurances to tenants and leaseholders who might be affected by the regeneration of council housing estates …” 26. LBHF’s “Vision” for the Fulham Regeneration Area, which includes the Earl’s Court and West Kensington Opportunity Area, is outlined in paragraphs 7.96 to 7.99. Paragraph 7.96 says “[the] residents of the housing estates will have been rehoused within the area in better quality homes and surroundings, and with better access to jobs and local facilities.” 27. The policy for the Fulham Regeneration Area, Strategic Policy FRA (“policy FRA”), begins by indicating the number of additional homes it seeks – 3,400 “(excluding any increase on estate lands)” – and the number of new jobs – 5-6,000. It then sets out the strategy, which it ties to the relevant provisions of the London Plan:    “…    The Opportunity Area is a significant part of the Fulham Regeneration Area which includes Fulham Town Centre. A part of the Opportunity Area is within KB Kensington & Chelsea. There is a substantial opportunity for major regeneration based on a phased comprehensive ap-proach to the Opportunity Area comprising the Earls Court exhibition complex (with its car park in Seagrave Road), the TfL Lillie Bridge depot and adjacent housing estates. As a residential led mixed use scheme, this area has the potential to become a major new neighbourhood for the borough and West London providing significant new housing and employment opportuni-ties. The original Earls Court building is located in the Royal Borough of Kensington & Chelsea and that borough broadly shares the council’s aspirations in its LDF Core Strategy. The London Plan identifies Earls Court and West Kensington as an Opportunity Area that ‘presents a signif-icant opportunity for regeneration comprising estate renewal and housing and employment growth’. The impact of development of this area will be to bring significant regenerative benefits to the rest of the regeneration area and surrounding area …”. The inset map in policy FRA shows the Fulham Regeneration Area, the Opportunity Area (less the part of it that is in RBKC’s area), Fulham Town Centre, the Strategic Sites, and the “Housing Estate Regeneration Area”, which includes the West Kensington and Gibbs Green estates. It is consistent with the core strategy proposals map, which also shows the estates, within the Opportunity Area and the Fulham Regeneration Area, as the “Strategic Site and Housing Estate Regeneration Area – FRA 1”. 28. The “Justification” for policy FRA is given in paragraphs 7.100 to 7.102. Paragraph 7.100 refers to the “council estates”, which it says “have high levels of deprivation and worklessness, and are often poorly laid out”. 29. Paragraphs 7.103 to 7.105 appear under the heading “Housing and decent neighbourhoods”. Paragraph 7.103 relates specifically to the future of the “council housing estates”:    “The Opportunity Area and its surroundings are dominated by a number of large council hous-ing estates which exhibit high levels of social, economic and physical deprivation with high lev-els of social rented housing. The council will seek phased regeneration over 20 years on West Kensington, Gibbs Green and part of the Clem Attlee estates to establish mixed and [balanced] communities and to help to support the economic regeneration which will, in turn, benefit resi-dents through improving employment opportunities and local shops and services. The process will only go forward following a programme of engagement with estate residents, and the provi-sion of opportunities for them to stay in the area.” Paragraph 7.104 refers to opportunities for enlarging and diversifying the housing stock. It says that “[if] es-tate regeneration takes place, the Seagrave Road site provides the potential to enable the first phases of housing estate regeneration by providing modern quality homes for many existing residents”. 30. In the text under the heading “Delivery” paragraph 7.113 says:    “Guidance on the regeneration of the Earl’s Court [and] West Kensington Opportunity Area will be by means of an area planning framework in the form of a Supplementary Planning Docu-ment (prepared jointly with the Royal Borough of Kensington & Chelsea and GLA) to ensure the co- ordination of phased development proposals and the provision of the required phased infrastructure.” Paragraph 7.114 explains that LBHF is working with TfL and the intending developer of the Earl’s Court exhi-bition centre complex and the Lillie Bridge depot “with a view to establishing whether there is a basis for en-tering into some form of joint venture to secure a phased, comprehensive regeneration scheme possibly in-corporating the West Kensington and Gibbs Green housing estates”. Paragraph 7.115 acknowledges that a “detailed assessment of development capacity will be required”, and goes on to say that it may be possible significantly to exceed the “conventional estimate” for additional homes and jobs in the period to 2031 “if the West Kensington and Gibbs Green housing estates are included …”. 31. Strategic Site and Housing Estate Regeneration Area Policy – FRA 1 (“policy FRA 1”) relates specifically to the “Earls Court and West Kensington Opportunity Area strategic site and housing regeneration area (Earls Court Exhibition Centre 2 and Seagrave Road car park, Lillie Bridge Depot, West Kensington and Gibbs Green estates, and adjacent land)”. It gives an indication of the number of new homes and new jobs planned in the Opportunity Area: 2,900 new homes “(excluding any increase on estate lands)” and 5,000 to 6,000 new jobs m LBHF’s area, and a total of 4,000 new homes, again “(excluding any increase on estate lands)”, and a total of 7,000 in the Opportunity Area as a whole. It goes on to refer to the housing estates:    “Regeneration of the West Kensington, Gibbs Green and registered Provider estates phased over up to 20 years will be considered as part of the comprehensive approach to the oppor-tunity area. All existing local residents should have the opportunity to be rehoused within the Opportunity Area or within its vicinity if proposals affect their homes.” This is followed by a lengthy description of the scale and nature of the regeneration LBHF aspires to achieve, including a considerable increase in housing. The final sentence of policy FRA 1 is this:    “Development must have regard to guidance set out in the Earls Court and West Kensington Opportunity Area Supplementary Planning Document.” 32. The “Justification” for policy FRA 1 is given in paragraphs 7.116 to 7.131. Paragraph 7.121 refers to the potential for “a combined Earls Court and TfL depot development” to “provide opportunities for the regenera-tion of West Kensington and Gibbs Green council estates”. It then says:    “This has led the council to consider the scope for a major regeneration scheme including the housing estates that could achieve long term benefits for the area based on:    o employment creation to more than replace the potential loss of the exhibition centre; and    o the long term regeneration of the West Kensington and Gibbs Green estates to tackle social, economic and physical deprivation and create decent neighbourhoods.” Paragraph 7.122 describes the housing estates and their perceived shortcomings. Paragraph 7.123 states:    “Regeneration of the estates could take place through refurbishment or involve a phased com-prehensive approach or a combination of measures. The presence of significant development sites within the opportunity area provides the potential to ensure that existing estate residents could remain in the area by providing opportunities for rehousing in one move as part of a phased redevelopment. To enable this to happen, there should be no net reduction in the amount of social rented housing in the opportunity area and development proposals for the Seagrave Road site should include, as part of the affordable housing provision, 25% of new housing as social rented, subject to estate regeneration coming forward and viability.” Paragraph 7.125 says that a “phased comprehensive mixed use approach may be more likely to attract de-velopment finance and enable estate regeneration”. Paragraph 7.131 refers to the indicative numbers of new homes and jobs sought by the London Plan in the Opportunity Area, and to the numbers given on policy FRA 1 “not including any estimates relating to the West Kensington and Gibbs Green estates”. However, it goes on to say:    “It may be possible to significantly exceed these figures in a phased comprehensive approach to the opportunity area but the capacity of any development would need to be considered in the light, in particular, of urban design considerations, land use mix, and provision of supporting fa-cilities and social infrastructure, transport capacity, environmental impact and the potential in-clusion and regeneration of the housing estates. The Supplementary Planning Document being prepared jointly with KB Kensington & Chelsea and the GLA is testing alternative quantums of development, including 6,000 and 8,000 new homes (in the opportunity area in both H&F and RBK&C) and will provide more detailed guidance.” 33. In chapter 8 of LBHF’s core strategy, which is entitled “Borough-wide Strategic Policies”, policy H1 sets out the “proposed London Plan target of 615 additional dwellings a year up to 2021” and provides “Indicative Housing Targets”, including targets for the Fulham Regeneration Area. In the “Justification” for policy H1, paragraph 8.7 says:    “The figures for the two opportunity areas in White City and Earl’s Court & West Kensington are as included in the London Plan. However, these targets are being reviewed as part of the preparation of planning frameworks for the area and could be exceeded, depending on the eventual land-use mix, urban design considerations and the extent of estate regeneration in the areas. The White City Opportunity Area Planning Framework and Earl’s Court and West Ken-sington Opportunity Area Supplementary Planning Document will provide more guidance on factors that will determine capacity.”                RBKC’s core strategy             34. Chapter 10 of RBKC’s core strategy relates to “Earl’s Court” and its future. Policy CV10, entitled “Vision for Earl’s Court in 2028”, says this “area will continue to offer a wide range of residential accommodation …”. Various opportunities for regeneration in the area are discussed. Under the heading “Diversity of Housing” paragraph 10.3.12 says that “[residential] development in Earl’s Court must deliver a mix of housing to reflect local and boroughwide need”, and that the Earl’s Court and West Kensington Opportunity Area “may deliver a minimum of 2,000 new dwellings”. Paragraph 10.4.4 says that a “joint Supplementary Planning Document” that will be prepared for the Opportunity Area by LBHF, RBKC and the GLA “will confirm the exact quantum of development and distribution of land uses across the entire site.” 35. Chapter 26 deals with the “Earl’s Court Exhibition Centre”. Paragraph 26.1.3 explains why this site is of “strategic importance”. The following paragraphs expand on the strategy for this part of RBKC’s area. Para-graph 26.2.1 says that the “full development capacity and exact disposition of uses across the Opportunity Area should be considered as part of the spatial planning for the Opportunity Area, through the joint Sup-plementary Planning Document (SPD)”, which will be prepared by LBHF and RBKC and will “be capable of being adopted by the GLA as an Opportunity Area Planning Framework”. Paragraph 26.3.2 says that the supplementary planning document will “provide a framework for a coordinated and phased development of the Earl’s Court and West Kensington Opportunity Area and may include some other land in Hammersmith and Fulham, and may fulfil the role of any Opportunity Area Planning Framework”. Paragraph 26.2.7 ex-presses RBKC’s desire for the “redevelopment” of the Opportunity Area with a “comprehensive mixed-use scheme”. 36. Policy CA 7 allocates the site of the Earl’s Court Exhibition Centre for development that will deliver a wide range of uses, including housing, offices, retail and cultural uses and others. These uses are described in paragraphs a. to h., under the heading “Land use allocation”. Paragraph a. says that the housing on the part of the site in RBKC’s area will be “a minimum of 500 homes” It says that this number “could be increased”, if certain things are done in LBHF’s area as part of “the masterplanning process conducted in the preparation of the SPD”.                The SPD             37. The SPD was jointly prepared by LBFIF and RBKC, working with the Mayor. It did not go through the statutory process for a development plan document. LBHF and RBKC consulted widely on draft versions of the SPD in October and November 2010, March and April 2011 and November and December 2011. Sus-tainability appraisals were prepared for it in March 2011 and March 2012. While it was being prepared the EREA was undertaken by consultants. The EREA report emerged in November 2011, and was taken into account by LBHF when it decided to adopt the SPD. 38. The SPD runs to 190 pages of text, divided into 13 chapters, in which various aspects of the regeneration of the Opportunity Area are dealt with. It also has a “Policy Context Appendix”. 39. In chapter 1 – its “Introduction” – under the heading “Status of this Document”, the SPD describes itself as “a Supplementary Planning Document … providing supplementary detail” to policies in the core strategies for the two boroughs, and also “Supplementary Planning Guidance” providing “supplementary detail” to the London Plan (paragraph 1.1). It adds that it “should be read in conjunction with the … London Plan, the [core strategies] and other relevant Development Plan Documents and SPDs” (ibid.). It says it is “a material con-sideration for the determination of any planning applications submitted within the [Opportunity Area]” (para-graph 1.2). Paragraph 1.3 says the SPD “is supported by a Sustainability Appraisal, and Equality Impact Assessment, a Statement of Consultation, an Adoption Statement and the Consultation Summary Report”. 40. Under the heading “Purpose of this Document”, paragraph 1.4 sets out four “overall objectives” of the SPD, the first of which is to “establish detailed guidance on the application of policies within the London Plan and the boroughs’ Development Plan Documents … that will be used to assess any planning applications in the [Opportunity Area]”. Paragraph 1.5 says that the Opportunity Area is “identified by description in Annex 1 of the London Plan (2011)”. Paragraph 1.7 acknowledges the need for “flexibility to achieve the authorities’ strategic vision of comprehensive redevelopment, as reflected in Key Principles HOI and PS1”, and makes plain that the SPD is “not intended to eliminate or constrain other acceptable development and/or strategies for achieving sustainable comprehensive regeneration in accordance with relevant London Plan and Core Strategy policies”. 41. On the “Policy Context” paragraph 1.8 says that the “entire site is identified in the London Plan as an Opportunity Area”, that the two core strategies “contain planning policies specific to development in the [Op-portunity Area]”, and that, together, these policies “require a minimum of 7,000 jobs and 4,000 homes in a comprehensive residential led mixed use development that includes offices, retail, social and community fa-cilities and a significant cultural destination”. It points out that the policies “are reproduced in full in the Ap-pendix”. Paragraph 1.9 refers to other policies applicable to “any redevelopment of the [Opportunity Area]”, and the Mayor’s other “theme based national, regional and local planning policies” that are also relevant. 42. In chapter 3, “Vision and Objectives”, paragraph 3.1 says that the SPD’s “vision reflects and is based on the aspirations” of the two local planning authorities and the Mayor for the Opportunity Area, “as established by both boroughs’ Core Strategies and the Mayor’s London Plan”, and that “[it] is not intended to exclude any acceptable development options which would accord with the London Plan and the Core Strategies”. Under the heading “West London’s New Urban Quarter”, paragraph 3.6 says this:    “There will be a substantial increase in the number of new homes in the area, with new housing for sale and rent at a range of prices and affordability. The Gibbs Green and West Kensington estates will be regenerated, with existing residents benefiting from greater housing choice, and higher quality, more suitable homes, designed with their needs in mind. All existing residents will be able to continue living in the area if they choose to do so, and the existing community will be enriched with a more varied, balanced and sustainable socio-economic mix.” 43. Chapter 5 of the SPD is entitled “Housing Strategy”. Paragraphs 5.4 to 5.6, which introduce the relevant “Policy Context”, list the principal policies of relevance in the London Plan and in each of the core strategies. Key Principles HO1 to HO5 and paragraphs 5.7 to 5.20 deal with “Estate Regeneration”. Key Principle HO1 is this:    “The authorities will require a comprehensive approach to the redevelopment of the OA and LBHF will expect comprehensive redevelopment to deliver estate regeneration.” Explaining that principle, paragraph 5.9 quotes the relevant part of policy FRA 1, and the text relating to the Opportunity Area in Annex 1 to the London Plan. Paragraphs 5.10 to 5.14 say this:    “5.10 With the future of the West Kensington and Gibbs Green estates in mind, LBHF is under-taking a review (known as [“the EREA”]of the economic benefits and disbenefits of the following four principle [sic] options:    o Minimum intervention;    o Minimal intervention and in-fill development;    o Comprehensive redevelopment as a standalone estate redevelopment; and    o Comprehensive redevelopment as part of a wider Earl’s Court masterplan development.    5.11 The initial conclusions are that estate redevelopment as part of a wider Earl’s Court mas-terplan development delivers the optimum benefits. LBHF, as landowner and being responsible for the estates as housing authority, has accepted and endorsed the conclusions contained within [the EREA], subject to the outcome of further consultation with local residents and any required consents from the Secretary of State    5.12 One of the supporting evidence documents that accompany this SPD is a Development Capacity Scenarios study. Scenario 1 in this study looks at a development scenario that does not involve the West Kensington and Gibbs Green estates whereas Scenarios 2 and 3 look at comprehensive redevelopment including the estates. A critique of each scenario is included in the study, which demonstrates that including the estates in comprehensive redevelopment has far greater benefits in terms of extending the urban grain, increasing public open space and improving connectivity.    5.13 The inclusion of the estates as part of a comprehensive phased redevelopment of the OA would provide opportunities for the reprovision of existing estate housing as part of a wider mixed tenure development. This would foster the creation of more mixed communities, which is a key tenet of Planning Policy Statement 1 on Delivering Sustainable Development. The utilisa-tion of these adjacent sites also provides better opportunities for getting an improved quality of social rented accommodation.    5.14 In consideration of the above, LBHF, as a planning authority, is of the opinion that any ap-proach to comprehensive redevelopment of the OA should include the West Kensington and Gibbs Green housing estates. Planning obligations will be put in place to ensure the delivery of estate redevelopment as part of any comprehensive approach to development in the OA.” 44. I shall come to Key Principles HO2, HO3, HO4, HO6 and HO7 when I consider ground 2. Key Principle HO5, however, is relevant here. It says that the “Phasing Strategy required in Key Principle PS1 … should demonstrate that the phasing and re-housing for the redevelopment of the West Kensington and Gibbs Green estates minimises disruption to existing residents”.                LBHF’s officers’ report for the meeting of full council on 19 March 2012             45. In their report to the meeting of the full council on 19 March 2012, at which it resolved to adopt the SPD, LBHF’s officers considered a number of issues that had arisen from consultation on the draft SPD (section 4). The first of these was “SPD or Area Action Plan?”. The officers said that a number of those consulted had contended that, instead of preparing a supplementary planning document, LBHF and RBKC ought to have produced an area action plan. The officers did not agree. They said that in their view an area action plan was “not necessary as up to date strategic policies are already set out in the London Plan and Borough Core Strategies”; that “the document as an SPD is appropriate and consistent with Government Guidance set out in Planning Policy Statement 12”; and that, in the light of “strategic policy FRA and strategic site policies FRA1 and FRA2”, the “site allocation of the opportunity area and the level of detail in those policies are such that a supplementary planning document is sufficient in the circumstances”.                PPS 12             46. When the SPD was prepared the Government’s policy for the preparation of development plans was in PPS 12: “Creating Strong, Safe and Prosperous Communities through Local Spatial Planning”, issued by the Government in 2008. PPS 12 has since been replaced by the National Planning Policy Framework, which was issued by the Government in March 2012. 47. PPS12 recognized the possibility of strategic allocations being made in core strategies, where particular sites were “considered central to the achievement of the strategy” (paragraph 4.6). It advised that where “strategic sites” were allocated in a core strategy “… [it] may be preferable for the site area to be delineated in outline rather than detailed terms, with site specific criteria set out to allow more precise definition through masterplanning using an area action plan (if required) or through a supplementary planning document (SPD)”, but that if it was “necessary to allocate land which has not already been allocated in the core strate-gy, a DPD rather than SPD must be used” (paragraph 4.7). 48. On area action plans and supplementary planning documents PPS 12 said this:    “5.4 Area action plans should be used when there is a need to provide the planning framework for areas where significant change … is needed. …    5.5 … Authorities may set criteria in their core strategy for identifying locations and priorities for the preparation of area action plans.    5.6 In areas of change, area action plans should identify the distribution of uses and their inter- relationships, including specific site allocations, and set out as far as practicable the timetable for the implementation of the proposals. …    …    6.1 A planning authority may prepare Supplementary Planning Documents to provide greater detail on the policies in its DPDs. SPDs should not be prepared with the aim of avoiding the need for the examination of policy which should be examined.”                Submissions             49. For the claimants, Mr Gregory Jones Q.C. submitted that the SPD is, in substance, a development plan document. It has all three of the attributes of an area action plan referred to in regulation 6(2)(a) of the 2004 regulations. In avoiding the statutory procedures for the production of development plan documents when they prepared and adopted the SPD, LBHF and RBKC fell into the same error as LBHF had done in pur-portedly producing a supplementary planning document for Shepherd’s Bush Market (see R. (on the applica-tion of Wakil) v Hammersmith and Fulham London Borough Council [2012] EWHC 1411 (Admin)). In the London Plan and the core strategies the comprehensive redevelopment of the West Kensington and Gibbs Green estates was seen as no more than a possibility. LBHF’s core strategy included several options for the regeneration of the estates, including (at paragraph 7.123) “refurbishment or … a phased comprehensive approach or a combination of measures”. The figures given for the number of new homes that could be pro-duced in the regeneration of the Opportunity Area deliberately exclude any additional housing that might be delivered through the demolition and comprehensive redevelopment of the estates. The selection of that op-tion was left to the SPD (see, for example, paragraph 8.7 of LBHF’s core strategy). It was the SPD that es-tablished the policy of comprehensively redeveloping the estates and rejected the other options for regener-ating the Opportunity Area (see, for example, paragraph 3.6, Key Principles HO1 and HO5, and paragraphs 5.10 to 5.14). This was not mere elaboration of the core strategy policies. For the first time, the SPD exclud-ed the option of retaining the estates. It identified an area of significant change. Even if the London Plan and the core strategies had already identified the Opportunity Area as an area of significant change, this could still be done by another development plan document, lower in the development plan hierarchy, when it set out policies for a specific site or sites. The SPD does what PPS 12 said should be done in area action plans. It ought to have been produced as an area action plan. 50. Mr Harris, Mr Elvin and Mr Katkowski submitted that the SPD is not, and was not required to be, an area action plan. It does not meet the definition of an area action plan in regulation 6(2)(a) of the 2004 regulations. It does not identify the Opportunity Area, or a smaller area within it, as an area of significant change. Nor does it contain the policies of LBHF and RBKC for the Opportunity Area. To identify an area as one of signif-icant change, within the meaning of regulation 6(2)(a)(ii) requires more than merely re-stating or adopting an identification already made in the development plan. In this case the identification of the Opportunity Area as an area of significant change was achieved in the London Plan and the core strategies. The Opportunity Ar-ea was designated in the London Plan, and its allocation was accomplished in the core strategies. What the SPD does is to provide supplementary guidance to the policies in the London Plan and the core strategies in which the development plan strategy for the Opportunity Area is set out. It does this with guidance that is not prescriptive, as, for example, its paragraph 1.7 makes clear. It was in the London Plan and the core strate-gies that the need for a comprehensive approach to regeneration was recognized. That this comprehensive approach could involve the demolition and redevelopment of the estates and the rehousing of their residents is also made plain in the London Plan and the core strategies. This case is clearly distinguishable on its facts from Wakil, where the document that purported to be a supplementary planning document had been adopted before LBHF’s core strategy was adopted, identified the Shepherd’s Bush Market area as an area of signifi-cant change, and contained the policies for that area. In this case, by contrast, the SPD is truly a supple-mentary planning document, which does not go beyond the proper function of such a document. Mr Elvin pointed out that the Mayor, when he adopts supplementary planning guidance, does so outside the con-straints of the 2004 Act and the 2004 regulations.                Discussion             51. The central question in this ground of the claim is whether the SPD is not a supplementary planning document but an area action plan, unlawfully produced outside the statutory system for the preparation of a development plan document. 52. Supplementary planning documents and supplementary planning guidance are not components of the development plan. They are always subordinate to the plan. Their purpose is to give additional guidance rel-evant to the provisions of the plan and consistent with them. Their subservience to the plan was emphasized in paragraph 6.1 of PPS 12 (see paragraph 48 above). 53. The crucial point here, in my view, is that the SPD was not the document that identified the area with which it is concerned, or any part of it, as an area of significant change. That had already been done in the development plan. 54. In my view, as Mr Harris, Mr Elvin and Mr Katkowski submitted, the concept of identifying an area as one of significant change, in regulation 6(2)(a)(ii) of the 2004 regulations, means establishing the principle of such change in a particular, defined area. Once this principle has been established the identification is com-plete. If a document is to be an area action plan it must be the document that achieves the identification. It must make what Mr Elvin referred to as the “primary identification”, or, as Mr Harris submitted, the “autono-mous identification” of the area as one of significant change. The sense of the word “identifies” in regulation 6(2)(a)(ii) is plainly the ordinary English meaning of the transitive verb “to identify”, namely to “[establish the identity of; establish who or what a given person or thing is; recognize” (The New Shorter Oxford English Dictionary (1993). 55. To construe the word “identifies” in regulation 6(2)(a)(ii) as if it meant “confirms the identification of or “acknowledges” or “provides policy or guidance for” would be to rob it of its true sense in its statutory context. It is clear from paragraphs (2)(a)(i) and (2)(a)(iii) of regulation 6 that the expression “identifies that area as an area of significant change …” in paragraph (2)(a)(ii) must have been meant to connote something different from the expression “relates to part of the area of the local planning authority” in paragraph (2)(a)(i), and dif-ferent also from the expression “contains the authority’s policies relevant to areas of significant change …” in paragraph (2)(a)(iii). 56. I think the wider construction of paragraph (2)(a)(ii) urged by Mr Jones would have consequences that Parliament cannot have intended. It would seem to preclude the preparation of supplementary planning documents for areas of significant change already identified in a development plan document. This is be-cause any document that contained guidance for development proposals within such an area would auto-matically be identifying an area of significant change. It would therefore have to be an area action plan (cf. R. (on the application of RWE Npower Renewables Ltd.) v Milton Keynes Borough Council [2013] EWHC 751 (Admin), at paragraphs 68 and 69). 57. But whether or not that does follow from what Mr Jones submitted, I am sure that the construction of reg-ulation 6(2)(a)(ii) submitted by Mr Harris, Mr Elvin and Mr Katkowski is right. 58. By the time the SPD came to be adopted, the requirement for urban regeneration in the Earl’s Court and West Kensington Opportunity Area had been firmly set in the development plan – in the London Plan and the two core strategies. 59. The London Plan clearly designates the Opportunity Area as an area in which significant change is re-quired as part of the spatial development strategy for London. Even in the absence of a site-specific alloca-tion in the London Plan it cannot be suggested that the West Kensington and Gibbs Green housing estates were left out of that area of significant change. They obviously were not. Table A1.1 in Annex 1 to the Lon-don Plan calls for a “comprehensive approach” (see paragraph 22 above). The “local authority housing es-tates” are one of the three areas specifically identified, the other two being the “exhibition complex” and the “Lillie Bridge Road depot”. The strategy does not require the estates to be left as they are, or suggest that they should merely be refurbished. On the contrary, “estate renewal” is explicitly one of the three main themes for the planning of the Opportunity Area, together with “housing and employment growth”. “Estate renewal” is a wide enough idea, in my view, to include redevelopment involving demolition and the erection of new housing to replace the existing. 60. Policy FRA and policy FRA 1 of LBHF’s core strategy and the text that goes with them could hardly be more explicit in what they say about the intended transformation of the Opportunity Area, including the hous-ing estates. The strategy for the Fulham Regeneration Area is not merely for physical change but for social and economic improvement as well (see paragraphs 27 to 32 above). The same may be said of the corre-sponding provisions of RBKC’s core strategy (see paragraphs 27 to 32 and 34 to 36 above). The two core strategies are clearly consistent with each other and with the London Plan. They set out, at length, the local planning authorities’ own strategic aims and policies for the Opportunity Area. 61. I accept as plainly correct the submission made by Mr Harris, Mr Elvin and Mr Katkowski that the core strategies refined the broad strategic initiative for the Opportunity Area in the London Plan into a more de-tailed but equally clear local strategy and a specific allocation of land, thus perfecting the identification of an area of significant change in the development plan. There was, therefore, no need for any area action plan to achieve that end. But there was room for further guidance in the form of a supplementary planning docu-ment. This was acknowledged in the core strategies themselves: in policy FRA 1 and paragraphs 7.113, 7.131 and 8.7 of LBHF’s core strategy, and in paragraphs 10.4.4, 26.2.1 and 26.2.3 of RBKC’s (see para-graphs 30 to 32 and 34 to 36 above). All of this was consistent with the Government’s advice in PPS 12, in-cluding the advice on the allocation of strategic sites in core strategies (see paragraph 47 above). 62. Viewed in the light of the policies for the Opportunity Area in the London Plan and the core strategies, the SPD cannot be seen as a document that identified an area of significant change in the sense of regulation 6(2)(a)(ii). 63. I do not accept that the guidance on “Estate Regeneration” in chapter 5 of the SPD amounts to an identi-fication of the estates as an individual area of significant change. That is a misconception of the guidance and its relationship to the policies of the development plan. The true position is this. The development plan refers specifically to the estates as a part of the Opportunity Area to which particular considerations apply, but within the overall strategy for comprehensive regeneration. The approach taken in the SPD is the same. The guidance it contains is not confined to the estates, though it focuses on them in some of its key princi-ples and text. Like the plan, the SPD relates to the whole of the Opportunity Area. It treats particular parts of the Opportunity Area individually when it has to, but when it does this it is not identifying an area of signifi-cant change. 64. The SPD was not used to make a site allocation, or as a vehicle for policy that ought to have been in the development plan. The strategic allocation of the Opportunity Area, including the estates, had already been made in the core strategies. The SPD did not do that. Nor did it introduce a new policy decision taken outside the processes in which the development plan was produced: that the West Kensington and Gibbs Green es-tates ought to be comprehensively redeveloped. Several passages in the SPD show an awareness of its role as guidance supplementing the strategy for the Opportunity Area in the development plan. In Key Principles HO1 to HO5 and their supporting text, as elsewhere in the SPD, the guidance is tied to the provisions of the development plan to which it relates (see paragraph 43 above). As Mr Harris submitted, in favouring a “com-prehensive approach” including “estate regeneration” in Key Principle HO1, the SPD is consistent with de-velopment plan policy. Paragraph 5.14 of the SPD records LBHF’s opinion, as local planning authority, that the housing estates ought to be included in any “comprehensive redevelopment of the [Opportunity Area]”. That LBHF takes this position in the SPD should come as no surprise to anyone familiar with what the de-velopment plan says about the regeneration of the Opportunity Area, and, in particular, the provisions of LBHF’s core strategy in policies FRA and FRA 1 and their explanatory text. But, as Mr Harris also stressed, the SPD itself makes clear, for example in paragraph 1.7, that the local planning authorities’ approach to re-generation, in accordance with relevant London Plan and core strategy policies, is a flexible one, and the guidance in the SPD is not intended to constrain that flexibility (see paragraph 40 above). 65. Unsurprisingly, the policies for the Opportunity Area in the London Plan and the core strategies do not dictate precisely how the challenges of regeneration are to be tackled in applications for planning permission. A pragmatic rather than prescriptive approach is adopted. But the housing estates are an integral part of the Opportunity Area, and of the strategic allocation of land for regeneration in the development plan. The fact that the housing figures given in LBHF’s core strategy do not include new housing that would result from “estate regeneration” does not mean that the redevelopment of the estates was excluded from the strategy. On the contrary, the redevelopment of the estates, involving demolition of the existing buildings and their residents being re-housed, is clearly embraced, not only in policies FRA and FRA 1 but also in the text that amplifies them – for example, in paragraphs 7.96, 7.103, 7.104, 7.115, 7.121, 7.123 and 7.131 (see para-graphs 26, 29, 30 and 32 above). This was clearly seen as conducive to the objectives of the strategy for the Opportunity Area being achieved. Indeed, as Mr Harris submitted, there would have been no sense in reas-suring existing tenants and leaseholders that they would be provided with new homes, in the same area, if it was expected that they would all be staying in the houses and flats they are living in now. In any event the redevelopment of the housing estates was properly the subject of the further guidance promised in para-graph 7.131 (see paragraph 32 above). It was open to the local planning authorities to endorse and elabo-rate on this theme in a supplementary planning document. Expressing their preference for it was not to ex-ceed any of their statutory powers in the 2004 Act and the 2004 regulations. 66. The suggestion made by Mr Jones in the course of argument that the identification of the Opportunity Area in the development plan might sometime disappear if one element of the plan or another were revoked or withdrawn is, I think, spectral. If that did happen the SPD would not then, as if by magic, be metamor-phosed into an area action plan. It would no longer be supplementary to policies for the Opportunity Area that had been removed. But it would not have become a development plan document because of that. 67. I do not think Mr Jones’ argument gains anything from the decision of Wilkie J. in Wakil. In that case the document that was ostensibly a supplementary planning document was held to be no such thing. LBHF had adopted it about 12 months before adopting its core strategy. The development plan current at the time did not clearly promote or allow for significant change in the area to which the document related – Shepherd’s Bush Market – and the core strategy was still in draft. It was only later, when the core strategy was adopted, that the strategy for wholesale regeneration of the area in question crystallized as policy in the development plan. On the facts before him Wilkie J. held that the document was, in substance, an area action plan (see paragraphs 88 to 90 of his judgment). The circumstances of the case before me are very different. Here, as I have said, the SPD did not allocate the Opportunity Area or the housing estates for comprehensive redevel-opment. It worked with an existing allocation in the development plan. The area of significant change had already been identified without the need for an area action plan to be prepared. The final step in assembling the framework of policy and guidance for the Opportunity Area, after the area of significant change had been identified and the policies for it put in place, was the publication of guidance in a supplementary planning document. And that final step had been foreshadowed in the development plan. 68. There was no appeal in Wakil. But Mr Harris and Mr Elvin argued that the decision in that case was based on a misunderstanding of the court’s jurisdiction, which, they said, was more limited than Wilkie J. had held. The question whether a particular document produced by a local planning authority ought to have been an area action plan rather than a supplementary planning document was, Mr Harris submitted, “a paradigm matter of judgment” for the authority, not a matter of construction for the court, so that the authority’s decision to proceed as it did could be overturned only if it was irrational. But one must be careful not to read more into what Wilkie J. said about the court’s jurisdiction than he intended. Whether the nature and degree of change planned for an area is significant or not will, I think, be a question primarily for the authority making that judgment. Whether a supplementary planning document conforms with the policies in a core strategy is also a matter of planning judgment (see the judgment of Laws L.J. in Persimmon Homes (Thames Valley) Ltd. v Stevenage Borough Council [2006] 1 W.LR. 334, at paragraphs 22, 29 and 30). Whether a document is what it purports to be – a supplementary planning document or an area action plan – because, according to the authority that has produced it, it has the defining characteristics of one or the other, is ultimately a question for the court. I do not believe Wilkie J. took a different view in Wakil, and I am not prepared to conclude that the duty of the court was overstated in that case. Anyway, following what I understand to have been Wilkie J.’s approach – as Mr Jones submitted I should – I find it impossible, on the facts before me, to accept the claimants’ argument on this ground of the claim. 69. Different facts will lead to different results. For example, in R. (Houghton and Wyton Parish Council) v Huntingdonshire District Council [2013] EWHC 1476 (Admin), Mr Charles George Q.C., sitting as a deputy judge of the High Court, held that the document in question – “the Framework” – did not establish the principle of the development to which it referred. This “had been done very broadly in the Core Strategy”, and the principle of such development was “not being further developed into a specific allocation through the Framework” (paragraph 39 of the judgment). The Framework was a “”how” document rather than a principled allocation” (ibid.). It did not, therefore, contain a site allocation for the purposes of regulation 2(1) of the 2004 regulations (paragraph 40). It was not a development plan document (paragraph 41). In my opinion this case is similar to that on its facts. 70. The final point is this. As Mr Elvin said, the Mayor’s plan-making powers, which are different from the lo-cal planning authorities’, do not include the power to promote or adopt an area action plan. Acting under the general powers conferred on him by sections 30 and 34 of the 1999 Act, however, the Mayor may publish supplementary planning guidance. I do not think the Mayor will have acted outside his own powers if he adopts the SPD in its present form, as supplementary planning guidance. Once he has done this, if he does, the SPD will be a material consideration in decisions on proposals for development in the Opportunity Area. 71. That analysis produces the following seven conclusions. 72. First, on the true construction of regulation 6(2)(a) and (4) it is my view, and plainly it was the Mayor’s and the local planning authorities’, that the requirement for the document in question to identify an area of significant change if it is to be an area action plan cannot be fulfilled if the area has already been identified as such in the development plan. To be absolutely clean this, I consider, is not merely a reasonable interpreta-tion of the relevant statutory provisions; it is the correct one. The concept of identification here means estab-lishing the identity of the area of significant change. It does not extend to the duplication or reflection of that process in a subsequent document. 73. Secondly, when LBHF and RBKC adopted the SPD the development plan process had already achieved the identification of the relevant area of significant change. No further or different act of identification was entailed in the preparation and adoption of the SPD. In truth, it was not the SPD that identified either the Opportunity Area or the housing estates as an area of significant change. This was done, deliberately and unambiguously, in the development plan. It was begun in the London Plan and it was completed in the core strategies. 74. Thirdly, therefore, the SPD is what LBHF and RBKC manifestly believed it to be, namely a supplemen-tary planning document, and not an area action plan. The local planning authorities did not misconstrue the relevant statutory provisions. They did not act irrationally. They did not set out to produce an area action plan. Nor should they have done so. As a matter of law, the SPD was not, and did not have to be, an area action plan. Though it relates to the Opportunity Area, as it had to if it was to supplement the relevant provi-sions of the development plan, it does not identify the Opportunity Area as an area of significant change. It is, in law as well as in substance, a supplementary planning document, properly so called. 75. Fourthly, LBHF and RBKC were not obliged to produce an area action plan for the Opportunity Area, or for any part of it. The requirement in section 17(3) of the 2004 Act for local planning authorities’ local devel-opment documents, taken as a whole, to set out their policies for the development and use of land in their areas was met. The allocation of the Opportunity Area had been made and the policies for it established in the development plan. There was nothing left for an area action plan to do. But the preparation of guidance in a supplementary planning document was both permissible and appropriate. 76. Fifthly, the SPD does what it is meant to do. It provides guidance supplementary to the development plan, without usurping the role of the plan. LBHF and RBKC reasonably regarded it as being in conformity with their core strategies, as regulation 13(8) of the 2004 regulations requires. Its guidance depends on the framework of policy in the development plan. Its description of the regeneration of the Opportunity Area is consistent with the plan, and expressed in similar language. 77. Sixthly, this case is very different on its facts from Wakil, and the decision in that case does not help the claimants here. 78. And seventhly, not only did the local planning authorities have the power to produce a supplementary planning document for the Opportunity Area, the Mayor for his part is entitled to produce supplementary planning guidance for the London Plan, and to do so in the form of the SPD. 79. Ground 1 of the claim therefore fails.                Ground 2: affordable housing and the EREA                            The policies for affordable housing in the development plan             80. Policy 3.11 of the London Plan, which deals with affordable housing targets, calls upon local planning authorities to “seek to maximise affordable housing provision ….”. It says that “60% of the affordable housing provision should be for social rent and 40% for intermediate rent or sale”. Authorities are enjoined to set tar-gets for affordable housing and for “social rented” and “intermediate housing”. Part C of Policy 3.11, in para-graph f, says that affordable housing targets “should take account of… [the] viability of future development, taking into account future resources as far as possible”. Policy 3.12 of the London Plan deals with the nego-tiation of affordable housing in individual schemes. It states:    “A The maximum reasonable amount of affordable housing should be sought when negotiating on individual private residential and mixed use schemes, having regard to:    …    c the need to encourage rather than restrain residential development (Policy 3.3),    e the size and type of affordable housing needed in particular locations    f the specific circumstances of individual sites.    B Negotiations on sites should take account of their individual circumstances including devel-opment viability, the availability of public subsidy, the implications of phased development in-cliding provisions for re-appraising the viability of schemes prior to implementation … and other scheme requirements.” Policy 3.14, “Existing housing”, states in part B, that the “[loss] of housing, including affordable housing, should be resisted unless the housing is replaced at existing or higher densities with at least equivalent floorspace”. In the text supporting Policy 3.14, paragraph 3.82 refers to the “renewal” of existing estates:    “Estate renewal should take into account the regeneration benefits to the local community, the proportion of affordable housing in the surrounding area (see Policy 3.19), and the amount of affordable housing intended to be provided elsewhere in the borough. Where redevelopment of affordable housing is proposed, it should not be permitted unless it is replaced by better quality accommodation, providing at least an equivalent floorspace of affordable housing.” 81. In LBHF’s core strategy “Borough Wide Strategic Policy – H2” (“Policy H2”), whose tide is “Affordability”, refers to the “borough wide target that at least 40% of all additional dwellings built between 2011-21 should be affordable” (paragraph a)). It says that LBHF “would prefer all additional affordable housing to be interme-diate and affordable rented housing unless a small proportion of new social rented housing is necessary in order to enable proposals for the regeneration of council or housing association estates, or the replacement of unsatisfactory accommodation, particularly in accordance with policies for the regeneration areas set out in this plan” (paragraph b)). In paragraph d) it says that “[in] negotiating for affordable housing and for an ap-propriate mix of intermediate affordable rented and social rented housing in a proposed development, the council will take into account” several considerations, two of which are:    ”    o Site size and site constraints; and    o Financial viability, having regard to individual circumstances of the site, the availability of pub-lic subsidy and the need to encourage rather than restrain residential development”. Policy FRA 1 contains these passages on the provision of housing and affordable housing in development proposed in the Opportunity Area:    “There should be a substantial overall net increase in housing. 40% of all new housing in the Opportunity Area (within H&F) should be affordable in accordance with Policy H2 – Affordability. With any proposals to replace existing social rented housing, the existing quantity should not be reduced but it should be redistributed across the Opportunity Area. Overall, new residential should have a mix of tenures, dwelling sizes and types, including family housing; and be pro-vided in densities and layouts that are compatible with high quality living environments for a mixed and balanced community.” and    “… Development proposals for Seagrave Road should provide for the opportunity to deliver ap-proximately 25% of all housing as social rented housing subject to estate regeneration coming forward, detailed analysis and viability. This will provide opportunities for tenants on local housing estates to be re-housed into better accommodation and to facilitate regeneration on those estates.”. Paragraph 7.124 of LBHF’s core strategy says that “40% of all new housing built in the Opportunity Area should be affordable housing in accordance with Strategic Policy H2”. 82. In RBKC’s core strategy several policies and their supporting text set out requirements for the provision of affordable housing in the regeneration of Earl’s Court, including paragraph 10.3.12, under the heading “Diversity of Housing”; Policy CA7, which deals specifically with the Earl’s Court Exhibition Centre; Policy CH1, “Housing Targets”, and Policy CH2, “Housing Diversity”. Policy CA7 makes “affordable housing as part of residential requirement” one of the items to be included in the planning obligation for development in Earl’s Court (paragraph q). Policy CH1 says that RBKC will “require affordable housing tenures to be provided such that they work towards a Borough-wide target of 85% social rented and 15% intermediate housing” (para-graph c). Policy CH2 of RBKC’s core strategy deals with “Housing Diversity”. On “Affordable Housing” it says in paragraph i that RBKC will “require developments to provide affordable housing at 50% by floor area on residential floorspace in excess of 800 sq.m gross external area”, and in paragraph p:    “where a scheme over 800 sq.m does not provide 50% of gross external residential floorspace for affordable housing, the applicant must demonstrate:    i. the maximum reasonable amount of affordable housing is provided through the provision of a viability assessment, using the GLA toolkit or an agreed alternative    ii. the exceptional site circumstances or other public benefits to justify the reduced affordable housing provision”. Paragraph q requires that affordable housing includes “a minimum of 15% intermediate housing” in the Earl’s Court ward.                The SPD’s guidance on affordable housing             83. I have already quoted paragraphs 5.10 and 5.11 of the SPD, which refer to the conclusions of the EREA (see paragraph 43 above). Key Principle HO2 of the SPD is this:    “Any] planning application involving the redevelopment of the Gibbs Green and West Kensing-ton housing estates will have to demonstrate that the proposals would not result in any net loss of affordable housing measured by floorspace and unit numbers.” Paragraph 5.15, which supports Key Principle HO2, refers to Policy 3.14B of the London Plan (see para-graph 80 above). It then says that LBHF “will also require that there is no net loss in unit numbers, in order to provide comfort to residents who live in a property within the estates, that they will have the opportunity to remain within the [Opportunity Area]”. Key Principle HO3 is this:    “Any planning application providing affordable units in order to facilitate the reprovision of housing for the residents of the West Kensington and Gibbs Green estate, should be accom-panied by an assessment of need. This should demonstrate that any affordable housing being provided will be sufficient in terms of size and adaptation to cater for the needs of residents on the existing estates who have expressed a desire to remain in the area.” Paragraph 5.16 says that “[direct] ‘like for like’ reprovision of the social housing in the Gibbs Green and West Kensington estates would not address current issues of overcrowding and hidden households or necessarily meet the housing needs of existing tenants”. It goes on to say that LBHF “will require any regeneration pro-posals to provide for the housing needs of the estates’ existing tenants and to provide sufficient housing op-tions for those existing leaseholders and freeholders who wish to stay to have the opportunity to purchase an equivalent property (in terms of bedroom numbers) to their existing property”. Key Principle HO4 is:    “25% of all new housing on the Seagrave Road site should be social rented and include a mix suitable to facilitate the reprovision of housing for an identified proportion of residents of the West Kensington and Gibbs Green estates”. Paragraph 5.18 says that the Seagrave Road site is “considered suitable for an early phase for redevelop-ment”, and that it is “therefore imperative that a certain quantum of affordable housing provided on [this] site is of a mix that reflects the needs of an identified proportion of the residents of the West Kensington and Gibbs Green estates, having regard to the requirements of Key Principle HO3”. Paragraph 5.19 says that “[in] addition to this, affordable housing will be required to top up to the 40% affordable housing target identi-fied in LBHF’s Core Strategy Policy H2, subject to viability”. 84. The SPD contains several key principles relating to “Tenure Mix”. These replicate the essential require-ments of development plan policy for the proportion of housing in new developments that should be provid-ed, if it is viable to do so. Paragraph 5.21 refers to and quotes Policy 3.12A of the London Plan. Key Principle HO6 is this:    “In LBHF, 40% of all new housing in the [Opportunity Area] should be affordable, subject to vi-ability. The priority will be the replacement of the existing social rented accommodation to meet the needs of the existing residents of the two housing estates. The remainder of the affordable housing should be intermediate or affordable rented.” Paragraph 5.22 refers to and quotes Policy H2 of LBHF’s core strategy. Key Principle HO7 is this:    “In RBKC, 50% of all gross external residential floorspace above 800 sqm should be affordable and provided on site within RBKC, subject to viability. A minimum of 15% of the affordable housing provision should be intermediate, with the remainder being social rented housing”. Paragraph 5.23 refers to the provisions for affordable housing in RBKC’s core strategy, including paragraphs 10.2 and 10.3.12 and Policies CP10, CA7 and CH2. It refers specifically to the requirement in Policy CH2 that where the affordable housing proposed is less than 50% of the total floor space it must be shown that this is the maximum reasonable amount of affordable housing.                The EREA             85. LBHF’s Head of Planning Regeneration, Ms Juliemma McLoughlin, explains the status of the EREA in her witness statement of 10 July 2012. She says (in paragraph 12) that the EREA is “not part of the SPD”, but a document that was “prepared by consultants instructed by LBHF’s Housing department to provide economic guidance as to the options available to it as landowner and housing authority”. She adds that “[the] findings of the EREA were considered by LBHF’s Cabinet on 7 November 2011 … and were taken into ac-count as a background document in preparing the SPD.” 86. The EREA report is dated November 2011. Its authors were Jones Lang LaSalle and Amion Consulting. In section 3 of the report they said they had considered a “range of estate regeneration options … in order to understand whether the regeneration of the estates as part of the comprehensive regeneration of the Op-portunity Area should be pursued from an economic perspective” The five options were:    “Option 1: Do minimum intervention (reference case) – under this option LBHF would continue to own, manage and maintain the estates …                           Option 2: Minimal intervention and infill development – under this op-tion, LBHF would again continue to own, manage and maintain the estates …                           Option 3(a): Comprehensive regeneration standalone estate rede-velopment – the estates would be comprehensively redeveloped and, in accordance with plan-ning requirements, the differentials in levels between the three land ownerships would be ad-dressed. …                           Option 3(b): Comprehensive regeneration: standalone estate rede-velopment – in order to test the costs and benefits of the alternative options, a variation of Op-tion 3(a) has also been developed, which assumes the existing levels are maintained …                           Option 4: Comprehensive regeneration: wider Earl’s Court redevel-opment – under this option, redevelopment would be undertaken of the combined LBHF, Cap-Co and TfL land, as part of the comprehensive redevelopment of the Opportunity Area.” The consultants concluded that Option 4 was the “best economic case and enables long term qualitative and quantitative objectives of regeneration to be realised” (section 5). 87. Table 4.1 of the EREA report showed the total number of “residential units” estimated for each of the op-tions, broken down into three categories – “Local Authority”, “New Affordable”, and “Private sector”. For all of the options the estimated proportions of affordable housing were below the percentages given in the relevant core strategy policies. Paragraph 4.2.1 of the report, headed “Gross direct residential units” said this:    “Table 4.1 sets out a summary of the total quantum of residential units that will be provided in the Opportunity Area under each of the options. In terms of the comprehensive regenera-tion/wider Earl’s Court redevelopment option (Option 4), it is estimated that a total of 7,583 res-idential units would be provided, some 4,282 more than under Option 3(a)/(b) and around 4,715 more than under Option 1 … .    …    Overall, Option 4 would provide 6,254 market units and 1,329 affordable units. This compares to 2,512 market units and 789 affordable units under Option 3. Option 1 and Option 2 would both provide 1,795 market units and 1,073 and 1,130 affordable units respectively.” Under the heading “Net additional residential units” paragraph 4.2.2 pointed out that “[in] determining the number of net additional residential units created under each option, the key issue to be addressed is the additionality of the redevelopment proposals …”. The 4,715 net additional residential units estimated for Op-tion 4, it said, “compares to 433 net additional residential units under Option 3(a)/(b) and 57 net additional residential units under Option 2.” 88. Paragraph 4.6 set out a “Summary of quantifiable benefits and net present value”. It summarized the “quantifiable benefits attributable to each option” in Table 4.4, which, it said, represented only a “broad as-sessment at this stage” and was “subject to consideration of detailed proposals”. The “net present value for each option was said to [reflect] the extent to which the benefits under each option outweigh the costs to the public sector”. The net present value for each option appears in the table: for Option 1, £21.8 million; for Op-tion 2, £28.9 million; for Option 3(a), £826.4 million; for Option 3(b), £988.6 million; and for Option 4, £3,783.1 million. The consultants went on to say:    “From the figures in Table 4.4, it is clear that Option 4 achieves the greatest positive net pre-sent value and delivers the largest amount of additional housing and new jobs – it would create over four times as many new jobs as Option 3(a)/ (b) and provide more than ten times as many additional homes. The net present value of Option 4 would have to be around 78% or 74% lower to be worse than Option 3(a) or Option 3(b). Consequently, for example, a very substan-tially lower quantum of floorspace would need to be approved and developed under Option 4 before either [Option] 3(a) or Option 3(b) was to offer a better economic return.” In Table 4.6 of the EREA report, where they were considering, among other things, the effectiveness of each option in contributing to the objective of increasing the supply of housing and providing “quality homes on sustainable new developments”, the consultants said that Option 4 would achieve a “[very] substantial in-crease in new housing supply on estates redevelopment and incorporation of CapCo and TfL sites”. 89. On 7 November 2011 LBHF’s Cabinet decided “provisionally” to “accept and endorse” the conclusions of the EREA report, “subject to the outcome of further consultation … with local residents, tenants and lease-holders and any required consents from the Secretary of State”. The officers reported the consultants’ con-clusion “that the comprehensive wider Earl’s Court redevelopment option (Option 4) is assessed to be the best option” (paragraph 2.3 of the officers’ report). They went on in section 3 of their report to consider what the next steps should be. In paragraph 3.4 they said that the EREA “makes clear the benefits that could arise from the estates being included in the comprehensive redevelopment of the area”, but that it also “recogniz-es some of the difficulties which need to be overcome before such redevelopment can become a realistic prospect”. In paragraph 3.5 they said that the EREA made a “compelling case” for LBHF “to explore further the significant possibilities presented by the scheme …”. 90. On 9 November 2011 the Mayor received from his officers a report commending to him the revised con-sultation draft of the SPD, in the light of which he decided to approve it. The report referred to the EREA, noting (in paragraph 19) that LBHF, “as landowner and being responsible for the estates as housing authori-ty” had provisionally accepted the consultants’ conclusions. 91. In February 2012 the consultants produced a report responding to the comments made in consultation to the EREA report. In its “Introduction”, in section 1, this report said that the EREA was “not intended to be an assessment of the impacts of the redevelopment on the two estates alone”, but that it had concentrated “on assessing the economic costs and benefits” to the two boroughs of the “inclusion or not of the estates within the proposed comprehensive regeneration scheme for the Opportunity Area”. In the “Conclusion” in section 3 the consultants rejected the suggestion that the EREA was “fundamentally flawed”. 92. In their report for the meeting of the full council on 19 March 2012, when dealing with the “Housing Strategy” of the SPD, LBHF’s officers referred to the EREA report as a “supporting evidence document” (paragraph 2.1). They said that the “Housing Strategy” reflected LBHF’s core strategy “by requiring 40% of housing in the Opportunity Area to be affordable, with the priority within this to be the replacement of the ex-isting housing, resulting from the redevelopment of the West Kensington and Gibbs Green estates” (ibid.). They went on to refer to a number of “supporting evidence documents … produced in order to inform [the] SPD” (paragraph 2.2). The EREA report was one of these. But the officers emphasized that “any applications for development would need to be accompanied by their own viability assessments”. They said that some of those consulted had objected to LBHF’s position, as local planning authority, that the housing estates should be included in “any comprehensive approach to redevelopment of the OA” (section 4). The consultants had been asked to consider those objections. They had done so, and had concluded, the officers said, that “re-development of the estates would improve the economic and social deprivation of the area and promote a more mixed and balanced community …”. The officers agreed. They said that in their view “the evidence in support of estate redevelopment outweighs the reasons given against estate redevelopment and that rede-velopment of the estates as part of a comprehensive approach to redevelopment of the opportunity area is necessary in planning terms” (ibid.). 93. In the “Consultation Summary Report” for the SPD, dated March 2012, criticisms of the EREA were rec-orded, including the objection that Options 3a, 3b and 4 showed a “large uplift in market housing”, which would be “unaffordable to many in the borough” (paragraph 4.21.6, under the heading “Estate Regeneration Options”). The report stated:    “… It was clarified that financial constraints had to be considered. It was clarified that option 4 would provide 24% affordable housing, providing 1,824 units, which could easily provide for the needs of existing estate residents as well as providing additional affordable housing to meet the needs of those on low and medium incomes. It was also clarified that although not affordable to many, market housing also contributes towards meeting housing need.”                Submissions             94. Mr Jones submitted that the SPD had to conform with development plan policy for affordable housing in the London Plan and the core strategies. But it was clear that none of the options assessed in the EREA would achieve the plan’s targets for affordable housing. The proportion of affordable housing in Option 1 would be 23%; in Option 2, 25%; in both of the sub-options in Option 3, 10%; and in Option 4, 11%. The de-cision to pursue Option 4 in the SPD betrays three errors of law. First, the assumed economic benefit of Op-tion 4, including the “substantial receipt” of £3 billion, was an irrelevant consideration and in any event could not be reconciled with the policy requirement for 40% of all new housing to be affordable (50% in the royal borough), or else it was a mistake of fact. Secondly, if LBHF and RBKC did accept that they would have to depart from the policies of the development plan for affordable housing if the level of growth predicted for Option 4 was to be achieved, they failed to explain why they decided as they did. And thirdly, when they adopted the SPD, LBHF and RBKC failed to have regard to a relevant consideration – what the economic benefit of comprehensive redevelopment might be if affordable housing were provided at a level consistent with development plan policy and Key Principle HO6 of the SPD. It is no answer to these submissions to say that the plan’s policies and the SPD’s guidance for affordable housing are as they are. The strategy of com-prehensive redevelopment, based on the conclusions in the EREA report, was clearly a strategy in conflict with development plan policy for affordable housing. LBHF and RBKC have not faced that conflict. The members must have thought that the strategy they were putting in place by adopting the SPD would deliver not only 40% affordable housing, which it would not, but also a substantial financial receipt for LBHF. They were misled. They were not advised as they should have been on these two matters (see R v Camden Con-don Borough Council, ex parte Cran [1995] RT.R. 346 and R (on the application of Cathco Property Holdings Ltd.) v Cygnor Gwynned Council & Finneys Ltd. [2008] EWHC 1462 (Admin)). 95. Mr Harris, Mr Elvin and Mr Katkowski submitted that Mr Jones’ argument on this ground was miscon-ceived. LBHF and RBKC did not have regard to any irrelevant consideration. The decisions of LBHF and RBKC to adopt the SPD and to express their support for the option that had emerged as the best in the EREA report were neither irrational nor unreasoned. The EREA report was procured by LBHF as landowner and housing authority. It was clearly relevant to LBHF’s decision on the disposal of the estates for redevel-opment. It was also properly taken into account in the decision to adopt the SPD. Neither the officers nor the members misunderstood its status or its significance. As paragraph 5.10 of the SPD acknowledges, the role of the EREA was to review “the economic benefits and disbenefits” of the options considered. The figure of “£3 billion” to which Mr Jones had referred was not a capital receipt for LBHF. It was the estimated net pre-sent value of development in the Opportunity Area. Economic benefit resulting from development in the Op-portunity Area plainly was a relevant matter in the planning of its regeneration. Neither officers nor members imagined that proposals for development in the Opportunity Area would avoid the requirement for their viabil-ity to be tested when the appropriate amount of affordable housing is fixed. Nothing said in the EREA report can change what development plan policy says about the need for affordable housing or the targets to which it refers. The relevant policies expressly acknowledge the need for development to be viable. So does the SPD. Key Principles HO6 and HO7 both contain the important words “subject to viability”. Individual schemes that do not achieve the proportion of affordable housing mentioned in the policies will nevertheless comply with those policies if it can be shown that the development would not be viable if more than the proposed amount of affordable housing had to be provided.                Discussion             96. I cannot accept Mr Jones’ argument on this ground. The submissions made by Mr Harris, Mr Elvin and Mr Katkowski are in my view correct. 97. The claimants acknowledged at the outset, as in my view they had to, that the guidance in the SPD is consistent with the housing policies of the London Plan and the core strategies. Paragraph 54 of the state-ment of facts and grounds in the claim form says this:    “On its face, the … SPD appeared to conform with adopted planning policy concerning afforda-ble housing targets in the … core strategies. In particular, Key Principle HO6 states that in LBHF, 40% of all new housing should be affordable subject to viability … .” 98. The policies for affordable housing in the development plan – in particular, Policy H2 of LBHF’s core strategy and Policy CH2 of RBKC’s – seek, in Hammersmith and Fulham, 40% of new housing to be provided as affordable housing, and in the royal borough 50%. The policies do not contain absolute requirements for a given amount of affordable housing in any particular scheme or on any particular site. They express strategic aims, and they set out relevant factors to enable authorities to judge how much affordable housing should be sought from developers, scheme by scheme and site by site. Thus they promote a consistent approach. They allow for the contingencies of individual schemes and individual sites. They express an aspiration for the stated proportions of affordable housing, but acknowledge economic reality. Underlying them is the recognition that developers will not be able to provide more affordable housing than is viable, and that to ex-pect them to do so would be counter-productive. In some cases a developer may be able to demonstrate that his scheme will only sustain a small proportion of affordable housing, considerably lower than the percentage level to which the relevant policies aspire. There may even be cases in which the developer can show that the development could not go ahead if he had to provide any affordable housing. In neither of those exam-ples would the development be in conflict with the policy, provided of course that the developer was able, through a solid viability appraisal, to prove that the economics of his project are as he contends them to be. 99. The SPD does not change any of that. Its guidance is clearly predicated on the development plan’s poli-cies for affordable housing as they stand. It does not misrepresent those policies or seek to vary them for the Opportunity Area. Paragraph 5.21 of the SPD summarizes Policy 3.12 of the London Plan. Key Principle HO6 and paragraph 5.22 reflect Policy H2 of LBHF’s core strategy; Key Principle HO7 and paragraph 5.23, the relevant provisions in RBKC’s, including Policy CH2. Those two Key Principles effectively confirm that the policies of the plan for affordable housing will apply to proposals in the Opportunity Area. Both acknowledge the test of viability deliberately written into the core strategy policies. They spell it out, in the words “subject to viability”. Thus the SPD leaves no room for doubt that the policies of the development plan for affordable housing will have to be applied to any relevant proposals, in the normal way, as section 70(2) of the 1990 Act and section 38(6) of the 2004 Act require. 100. I can see nothing unlawful in the way the EREA was used in the preparation of the SPD. 101. In my view, as Mr Harris, Mr Elvin and Mr Katkowski, submitted, the EREA was relevant not only to the decision LBHF had to take as landowner and housing authority on the disposal of the housing estates, but also to the process it went through as a local planning authority in the preparation and adoption of the SPD. The EREA report contained the consultants’ analysis of the economic strengths and weaknesses of each of the options for the regeneration of the Opportunity Area that they had been asked to consider. The consult-ants’ conclusions on the economic benefits and disadvantages of each option were, in my view, properly treated as a relevant part of the evidence on which the guidance in the SPD was based. There was nothing wrong in LBHF and RBKC heeding those conclusions and giving them due weight when formulating the guidance. I think they would have been remiss if they had not. The economic aspect of regeneration features in the policies for the Opportunity Area both in the London Plan and in the core strategies. There is, in my view, no reason why the economic advantages of the favoured option for the regeneration of the Opportunity Area should not have influenced the supplementary guidance for those policies. 102. Mr Jones argued that by accepting the consultants’ conclusions on the options they had considered LBHF and RBKC took a position irreconcilable with their own core strategy policies for the amount of afford-able housing to be provided in new residential development. 103. I do not see any force in that argument. 104. The EREA did not, and could not, add to or alter the development plan’s policies for affordable housing. The SPD does not give it the status or effect of a development plan policy, or of the guidance in a supple-mentary planning document. The consultants’ conclusions did not constitute a new or alternative policy for affordable housing applicable to development within the Opportunity Area. The relevant development plan policies remained as they were, entirely intact, in the London Plan and the core strategies. I do not believe either the officers or the members thought anything else. 105. Nowhere in the material relating to the preparation and adoption of the SPD does one find any hint that the EREA was regarded by the local planning authorities as a source of planning policy. The SPD does not refer to it as policy. Paragraph 5.11 mentions the “initial” view that the redevelopment of the estates would deliver “the optimum benefits”, and to LBHF, as landowner and housing authority, having accepted and en-dorsed the conclusions of the EREA, subject to the outcome of further consultation with residents. Paragraph 5.14 records LBHF’s “opinion” as local planning authority that the West Kensington and Gibbs Green hous-ing estates should be included in “any approach to comprehensive redevelopment of the [Opportunity Area]”. None of this means that the EREA report has been transformed into policy, or that in a development control decision LBHF and RBKC will gauge the merits of proposals against its contents and conclusions instead of the relevant policy and guidance. 106. None of the options analysed in the EREA was thought likely to produce levels of affordable housing that would meet the general targets set in the development plan for each of the two boroughs. But this does not mean that the plan’s policies for affordable housing, or Key Principles HO6 and HO7 of the SPD, were compromised by the support expressed in the SPD for the kind of development represented by Option 4. 107. Table 4.1 of the EREA report shows estimated levels of affordable housing for all of the options well below the 40% and 50% levels indicated in the core strategy policies. The figures are not hard to grasp. However, as Mr Harris submitted, it is important to look beyond the arithmetic on which the claimants rely, focusing as it does on the respective proportions of affordable housing in the several options, and to notice the net total number of additional dwellings and affordable dwellings for each. This was a consideration to which the consultants gave significant weight in their analysis, as one can see in paragraphs 4.2.1 and 4.2.2. They said “additionality” was the “key issue”, and this was clearly greatest in Option 4. As Table 4.1 showed, by far the largest increase in housing was promised by that option. This is also the option in which most new affordable dwellings would be provided: 798, compared with 542 in Option 1, 599 in Option 2, and 258 in each of Options 3(a) and 3(b). The 798 affordable dwellings estimated for Option 4 is not only, in absolute terms, the greatest amount, but also therefore, if compared with the total numbers of new homes estimated for each of the other options, it would equate to a much higher proportion of affordable housing than the percentages referred to by Mr Jones. So the advantages of Option 4 over the other options in its yield of new housing and affordable housing are obvious. 108. The fallacy in the claimants’ argument is that the options in the EREA were necessarily in conflict with development plan policy because, on the consultants’ analysis, they offered less than the target levels of af-fordable housing. That is not so. 109. In the first place, the options did not have to comply with the development plan. They were not schemes of development. They were hypotheses based on assumptions. The consultants did not have to justify them against the policies of the plan. That was no part of their remit. 110. Secondly, even if one looks at the options as if they were real proposals, they were not in conflict with the plan simply because the likely proportion of affordable housing in them was less than the percentage re-ferred to in policy. As I have said, the policies permit development with lower levels of affordable housing than the targets. The principles stated in the SPD, and the guidance that goes with them, do not deviate from those policies. Any application for planning permission for the development of housing in the Opportunity Area will have to be determined in accordance with the development plan unless material considerations in-dicate otherwise. Where the affordable housing policies of the plan are relevant, they will have to be applied, and the proposed development tested against them. The EREA report does not relieve a developer of the burden that rests upon him to show that his scheme cannot carry the amount of affordable housing sought by the relevant policy. This will have to be considered in the light of an up to date viability appraisal prepared for a real project when it comes forward. 111. As Mr Harris submitted, the viability of providing a higher proportion of affordable housing than was foreseen in the EREA will fall to be considered in the development control process. It will not be tested against the conclusions in the EREA report. It will be tested against the relevant provisions of the develop-ment plan, and in the light of circumstances as they are at the time. The circumstances may be different from those assumed in the EREA I do not think there was any misunderstanding about this when the SPD was adopted. In their report for the meeting of the full council on 19 March 2012 LBHF’s officers reminded the members that applications for planning permission for housing would require “their own viability assess-ments”. As the members knew, it was in the light of this work that the proposed amount and tenure of af-fordable housing in a particular scheme would have to be judged. 112. I do not believe that LBHF and RBKC, when they decided to adopt the SPD, assumed that a develop-ment embodying Option 4 would be able to provide affordable housing at the level to which the core strate-gies aspire. The report prepared by LBHF’s officers for the Cabinet meeting in November 2011 neither says nor implies that it would. Nor does the officers’ report for the meeting on 19 March 2012. Nor does the SPD itself. There was, in my view, no misdirection, and no mistake of fact. The members were not misled. The conclusions in the EREA report, and the advice the officers gave the members about those conclusions, are in my view clear and sufficient. I do not accept that this is a case of the kind referred to in ex parte Cran and in Cathco Property Holdings Ltd. (at paragraphs 33 to 35 in the judgment of Collins J.), where an officers’ report can fairly be criticized for not having given the members enough information and advice on the matters they had to decide. 113. But in any event the premise of Mr Jones’ submissions on this point is, I think, false. The local planning authorities did not accept, and did not have to accept, that they would need to depart from, or fail to apply, the policies of the development plan for affordable housing if Option 4 were selected. There was, as I have said, nothing incompatible in principle between Option 4 and the affordable housing policies in the plan. There was no conflict of this kind for LBHF and RBKC to resolve, or for the SPD to admit and explain. 114. Nor do I accept that LBHF was under the illusion that the figure of about £3.8 million calculated by the consultants as the net present value of Option 4 represented a likely receipt for itself, or that this notion in-fluenced its decision to support that option. The net present value of each of the options, as one facet of the relative economic performance of each, was not an irrelevant consideration. It was in my view undoubtedly relevant in the decision, on planning grounds, to prefer one option for the regeneration of the Opportunity Area to any of the others. As Mr Harris pointed out, and as is plain from the EREA report, the net present value calculated by the consultants does not represent a capital receipt to LBHF. It represents, in a global figure, the economic benefit of a comprehensive scheme of development for the entire Opportunity Area on the assumptions the consultants had made. For the local planning authorities to have regard to it was not to act against the letter or the spirit of the development plan policies for affordable housing, nor was it irrational or otherwise unlawful. 115. I also reject the submission that when they adopted the SPD, LBHF and RBKC ought to have consid-ered what the economic benefits of “comprehensive redevelopment” might be if affordable housing were to be provided at a level consistent with the general aspirations of development plan policy and Key Principle HO6 of the SPD. First of all, this is not something that relevant development plan policy requires local plan-ning authorities to take into account when producing supplementary planning documents. Secondly, when they produced the SPD, LBHF and RBKC were not re-writing the development plan, nor were they making a decision on an application for planning permission. The balancing of economic, social and environmental considerations, with the aid of relevant policy and guidance, is the business of development control. It is a matter for the judgment of the decision-maker when firm proposals have been submitted for planning per-mission. It is not an exercise that a local planning authority has to go through in the abstract when preparing guidance for such decisions in a supplementary planning document. And thirdly, the fatal flaw in the argu-ment, once again, is that it ignores the flexibility inherent in the development plan policies for affordable housing. Those policies, as I have said, put the onus on a developer to satisfy the decision-maker that his project would not be worth his while if more affordable housing had to be provided as well as any other bene-fits or infrastructure whose cost he is expected to bear. This principle runs through policy 3.12 of the London Plan, policy H2 of LBHF’s core strategy, policy CH2 of RBKC’s, and the relevant Key Principles and guid-ance in the SPD. 116. Ground 2 of the claim therefore fails.                Ground 4: social housing                            Development plan policy for social housing             117. Policy 3.10 of the London Plan contains a definition of affordable housing, which includes “social rented housing” and “intermediate housing”. It sets criteria by which to judge whether housing is affordable or not. Paragraph 3.61 says that “social rented housing” should meet the criteria in Policy 3.10 “and the rented housing owned and managed by local authorities or registered social landlords, for which guideline target rents are determined through the national rent regime or be provided by other bodies under equivalent rental arrangements …”. This definition, in a slightly condensed form, appears also in the glossary in LBHF’s core strategy. I have already referred to part B of Policy 3.14 of the London Plan, which resists the loss of afford-able housing (see paragraph 80 above). 118. I have also referred to policy H2 of LBHF’s core strategy, which relates in part to the preferred tenure of additional affordable housing (see paragraph 81 above). Paragraphs 8.23 and 8.24 in the text supporting policy H2 of the core strategy say this:    “8.23 The council will seek new social rented housing where this will enable the regeneration of existing estates and the provision of better accommodation (e.g. quality, dwelling size and con-ditions) for existing social rented tenants; and where it is possible to achieve a better mix of tenure and a more mixed and balanced community in the area. The policy for regeneration ar-eas set out details where applicable.    8.24 The council considers that it should be possible to meet newly arising urgent need without increasing the overall amount of social rented housing in the borough (H&F Housing Market Assessment). In view of this, the overall net increase in affordable housing in the borough should be intermediate and affordable rented housing but there should be no net decrease in social rented housing (measured in habitable rooms) in the White City and Earls Court and West Kensington Opportunity Areas.” 119. Paragraph 7.104 of LBHF’s core strategy says that “[across] the regeneration area the quantity of social rented housing should not be reduced, but the social rented dwelling size mix should be improved commen-surate with need.” I have mentioned the parts of policy FRA 1 that relate to proposals for the replacement of existing social rented housing (see paragraph 31 above), and the requirement in paragraph 7.123 that there should be “no net reduction in the amount of social rented housing” in the Opportunity Area (see paragraph 32 above).                The SPD             120. Key Principles HO2, HO3, HO4 and HO6 of the SPD, and the guidance that goes with them, all relate, or relate in part, to the provision of social housing in the Opportunity Area (see paragraphs 83 and 84 above).                Submissions             121. Mr Jones submitted that the SPD had to conform with the policies for social housing in the London Plan and the core strategies, and not merely with their policies for affordable housing generally. The distinction between social housing and other forms of affordable housing is important. The demolition of the existing housing estates in the Opportunity Area would lead to the loss of about 760 dwellings, about 590 of which are social rented. But, in conflict with core strategy policy, the SPD does not expressly require the replace-ment of all the social rented housing that will be lost when the estates are demolished, only an undefined amount of replacement “affordable” housing. If 200 social rented dwellings come forward on the Seagrave Road site, there could be a shortfall of as many as 390. Key Principle HO6 requires only that 40% of all new housing in the Opportunity Areas should be “affordable”, albeit with “priority” given to replacing existing social rented accommodation to meet the needs of existing residents of the estates. This implies that social rented accommodation on the estates will, or may well be, replaced by other forms of affordable housing. It threat-ens a net reduction of social rented housing in the Opportunity Area. Key Principle HO7 does not apply to the West Kensington and Gibbs Green estates, because they are not in the royal borough. Paragraph 5.16 of the SPD discourages the “[direct] ‘like for like’ reprovision of the social housing” in those estates. So there could be a huge net reduction of social rented housing in the Opportunity Area. By allowing for a possible net re-duction in social housing the SPD is in breach of regulation 13(5) of the 2004 regulations (see paragraph 83 above). 122. Mr Harris, Mr Elvin and Mr Katkowski submitted that the claimants’ argument rests on a misreading of the relevant provisions of the development plan and the SPD. Neither the core strategy policies for affordable housing and social housing nor Key Principles HO2, HO3, HO4 and HO6 of the SPD and the text explaining them allow any net reduction in social rented accommodation in the Opportunity Area, or the replacement of existing social rented housing in the West Kensington and Gibbs Green estates with accommodation inferior to that already provided. Under the guidance in the SPD, residents of social housing in the estates will be offered accommodation suitable for them in any redevelopment. The SPD does not dilute the development plan policy commitments for the provision of affordable housing, and social housing in particular.                Discussion             123. I see no merit in this ground. As Mr Harris, Mr Elvin and Mr Katkowski submitted, it seems to be based on a misunderstanding of the relevant provisions of the development plan and the SPD. 124. Social housing – or social rented housing – is one type of affordable housing. There are others. Both development plan policy and the guidance in the SPD distinguish between them wherever it is necessary to do so. Specific references to social housing are not to be confused with generic references to affordable housing. 125. Policy 3.14B of the London Plan resists the loss of affordable housing (see paragraph 80 above). This principle applies to affordable housing generally, including social housing. 126. Policy H2 of LBHF’s core strategy expresses a preference for additional affordable housing to be “in-termediate and affordable rented housing” unless new “social rented housing” is required to replace what is lost through redevelopment of existing housing estates, or accommodation that is unsatisfactory (see para-graph 81 above). The text in paragraph 8.23 explains that “new social rented housing” will be sought when this will enable “the regeneration of existing estates and the provision of better accommodation … for existing social rented tenants”; and “where it is possible to achieve a better mix of tenure and a more mixed and bal-anced community in the area” (see paragraph 118 above). 127. These general principles are repeated in the provisions of the core strategy for the Fulham Regenera-tion Area. Policy FRA1 and the text in paragraphs 7.103, 7.104 and 7.123 set out the approach LBHF will take to the provision of new social housing in the Earl’s Court and West Kensington Opportunity Area (see paragraphs 29 and 32 above). It is principally in those provisions that one finds the relevant “details” referred to in the last sentence of paragraph 8.23 of the core strategy. There can be no mistaking LBHF’s resolve to prevent any net reduction in the amount of social rented housing in the Opportunity Area. One sees it in paragraph 7.123. And one sees it in policy FRA 1 itself, which says that in “any proposal to replace existing social rented housing, the existing quantity should not be reduced but … should be redistributed across the opportunity area”. Development proposals for Seagrave Road are dealt with separately, in the requirement for “approximately 25% of all housing as social rented housing subject to estate regeneration coming for-ward, detailed analysis and viability”. 128. I do not think it can be suggested that the SPD indicates any different approach. In its relevant key prin-ciples and guidance it repeats and relies on the commitment of LBHF’s core strategy at least to maintain the existing amount of social rented housing in the Opportunity Area. 129. Key Principle HO2 makes it clear that there should be no net loss of affordable housing in proposals involving the development of the Gibbs Green and West Kensington estates (see paragraph 83 above). 130. The interests of existing tenants of social housing in the estates are not neglected. They are explicitly protected. Key Principle HO3 requires any affordable housing in proposals for redevelopment in which resi-dents of the West Kensington and Gibbs Green estates are to be re-housed should be suitable for them. Its requirement for “an assessment of need” in any proposals providing affordable housing is intended to facili-tate the provision of replacement housing for the residents of the estates (see paragraph 83 above). The as-sessment of need must demonstrate that any affordable housing provided will meet the needs of residents of the estates who want to stay in the area (ibid.). Paragraph 5.16 of the SPD, elaborating on this key principle, explains that the mere “like for like” re-provision of the social housing in the Gibbs Green and West Kensing-ton estates is not what LBHF and RBKC want to see. This does not mean that the SPD has weakened the commitment to maintaining at least the existing amount of social housing in the Opportunity Area. What it means – and there really can be no doubt about this – is that “like for like” replacement of social housing would not be sufficient because it would not overcome “overcrowding and hidden households” and would not ensure that the “housing needs of existing tenants” will be met. Paragraph 5.16 says precisely that. It also requires development not only to provide for the housing needs of the “existing tenants” on the estates but also to ensure that any existing leaseholder or freehold owner who wants to stay will be able to move into a home with as many bedrooms as the one that he or she already has (see paragraph 83 above). 131. Key Principle HO4 reflects policy FRA1 in what it says about the provision of social rented housing on the Seagrave Road site. It repeats the requirement in policy FRA 1 and in paragraph 7.123 of LBHF’s core strategy that 25% of all new housing on the Seagrave Road site should be social rented, so that tenants on the existing estates have the chance to be re-housed in better accommodation. This is clearly intended to ensure that existing tenants in the estates will be re-housed in better accommodation. But it does not over-ride the requirement for replacement affordable housing to be provided in full. 132. Key Principle HO6 draws on policy H2 of the core strategy in its requirement for 40% of all new housing in the Opportunity Area to be affordable, “subject to viability”. The “priority” given to the “replacement” of ex-isting social rented accommodation “to meet the needs of existing residents of the two housing estates”, with the balance of the affordable housing being intermediate or affordable rented, is in line with the principle stated in the second sentence of paragraph 8.24 of the core strategy (see paragraph 84 above). 133. It is clear, therefore, that neither the core strategy nor the SPD allows any net loss of social rented ac-commodation in the Opportunity Area. Proposals that would result in that would be contrary to the develop-ment plan and contrary to the SPD. 134. In my view, the guidance in the SPD relating to housing, affordable housing, and social rented housing is, in my view, wholly consistent with the policies of the London Plan and LBHF’s core strategy. Nor is there any conflict between the SPD and the equivalent provisions for housing and affordable housing in RBKC’s core strategy. The policies of the development plan align with each other. And the principles and guidance in the SPD align with them. 135. There is no breach of regulation 13(5) of the 2004 regulations. The SPD is not a development plan document, so regulation 13(5) does not apply to it. And even if it did apply there would be no breach because the SPD does not “[contain] a policy that is intended to supersede another policy”. 136. Nothing I have said in discussing this ground of the claim should be seen as interfering with the local planning authorities’, or the Secretary of State’s, planning judgment. What I have had to consider is whether the claimants have managed to expose anything unlawful in the relationship between the SPD and the provi-sions of the development plan for social housing, or in the provisions of the SPD itself. In my view they have not. But if, as I suspect, the claimants’ teal concern here is that the SPD softens the local planning authori-ties’ commitment to retaining at least the existing amount of social housing in the Opportunity Area, and seeking an increase greater than any loss suffered through redevelopment, I believe they are wrong. The SPD does not do that. 137. Ground 4 of the claim therefore also fails.                Ground 5: SEA                            The regime for SEA             138. The Environmental Assessment of Plans and Programmes Regulations 2004 (“the SEA regulations”) transpose into national law the provisions of Directive 2001/42/EC on the assessment of the effects of certain plans and programmes on the environment (“the SEA directive”). 139. Article 2(a) of the SEA directive provides that “plans and programmes” means “plans and programmes” that are “subject to preparation and/or adoption by an authority at national, regional or local level or which are prepared by an authority for adoption, through a legislative procedure by Parliament or Government” and also “required by legislative, regulatory or administrative provisions …”. A similar definition appears in regula-tion 2(1) of the SEA regulations. 140. Under article 3 of the SEA directive SEA is required for “plans and programmes … likely to have signifi-cant environmental effects” if they are “prepared for … town and country planning or land use and … set the framework for future development consent of projects listed in Annexes I and II to [the EIA directive]” (article 3(1) and (2)(a) of the SEA directive). Regulation 5 of the SEA regulations provides for the assessment of plans or programmes prepared on or after 21 July 2004. Under regulation 5(1) an authority is required to carry out the assessment before the adoption or submission of the plan or programme. The description of a “plan or programme” in regulation 5(2) is one that:    “(a) is prepared for … town and country planning or land use, and    (b) sets the framework for future development consent of projects listed in Annex I or II to [the SEA Directive] 141. Section 19(5)(a) of the 2004 Act provides that a local planning authority must “carry out an appraisal of the sustainability of the proposals in each development plan document”. Section 180(5) of the Planning Act 2008 (“the 2008 Act”) amended section 19(5)(a), with effect from 6 April 2009, to remove the requirement in that provision for supplementary planning documents to be subject to sustainability appraisal, and thus SEA 142. Article 4(3) of the SEA directive provides that “[where] plans and programs form part of a hierarchy, Member States shall, with a view to avoiding duplication of the assessment, take into account the fact that the assessment will be carried out, in accordance with this Directive, at different levels of the hierarchy. For the purpose of, inter alia, avoiding duplication of an assessment, Member States shall apply Article 5(2) and (3)” (see also regulation 12(3) of the SEA regulations). 143. Article 5(1) of the SEA directive provides that “[where] an environmental assessment is required under Article 3(1) an environmental report shall be prepared in which the likely significant effects on the environ-ment of implementing the plan or programme, and reasonable alternatives taking into account the objectives and the geographical scope of the plan or programme, are identified, described and evaluated.” The infor-mation required in the environmental report is referred to in Annex I to the SEA directive. Regulation 12(3) of the SEA regulations requires the environmental report to include “such of the information referred to in Schedule 2 … as may reasonably be required”, taking account of “(a) current knowledge and methods of as-sessment”, “(b) the contents and level of detail in the plan or programme”, “(c) the stage of the plan or pro-gramme in the decision-making process”, and “(d) the extent to which certain matters are more appropriately assessed at different levels in that process in order to avoid duplication of the assessment”. 144. The information referred to in Schedule 2 includes, in paragraph 6, information on the “likely significant effects on the environment, including short, medium and long-term effects, permanent and temporary effects, positive and negative effects, and secondary, cumulative and synergistic effects, on issues such as … (b) population; (c) human health; … (j) material assets; …”; in paragraph 8, an “outline of the reasons for select-ing the alternatives dealt with, and a description of how the assessment was undertaken including any diffi-culties … encountered in compiling the required information”; and in paragraph 10, a “non-technical sum-mary…”. 145. Article 9(1) of the SEA directive provides for the publication of “[information] on the decision”, including “(b) a statement summarising how environmental considerations have been integrated into the plan or pro-gramme Regulation 16 of the SEA regulations appears in Part 4, which provides for the post-adoption pro-cedures in the SEA process. It requires the responsible authority “[as] soon as reasonably practicable after the adoption of a plan for which an environmental assessment has been carried out …” to “take such steps as it considers appropriate to bring to the attention of the public” certain information (paragraph (1)(b)). The information includes (at paragraph (1)(b)(iii)) “the address (which may include a website) at which a copy of [the plan or programme] and of its accompanying environmental report, and of a statement containing the particulars specified in paragraph (4), may be viewed or from which a copy may be obtained”. Under para-graph (2) the authority is required to inform those who were “public consultees for the purposes of regulation 13” of the matters referred to in paragraph (3), which include, at paragraph (3) (c)(iii), the address at which “a statement containing the particulars specified in paragraph (4) ” may be viewed, or a copy obtained. The par-ticulars referred to in paragraphs (1)(b)(iii) and (3)(c)(iii) are specified in paragraph (4). They are:    “(a) how environmental considerations have been integrated into the plan or programme;    (b) how the environmental report has been taken into account;    (c) how opinions expressed in response to –    (i) the invitation referred to in regulation 13(2)(d);    (ii) action taken by the responsible authority in accordance with regulation 13(4),    have been taken into account;    (d) how the results of any consultations entered into under regulation 14(4) have been taken into account;    (e) the reasons for choosing the plan or programme as adopted, in the light of the other rea-sonable alternatives dealt with; and    (f) the measures that are to be taken to monitor the significant environmental effects of the im-plementation of the plan or programme.”                Guidance on SEA             146. In 2001 the European Commission issued guidance on the implementation of the SEA directive (“Im-plementation of Directive 2001/42 of the Assessment of the Effects of Certain Plans and Programmes on the Environment”). The Government issued its own guidance in September 2005, “A Practical Guide to the Stra-tegic Environment Assessment Directive”. 147. On Article 2 of the SEA directive, paragraphs 3.15 and 3.16 of the Commission’s guidance say this:    “3.15 Another important qualification before a plan or programme to be subject to the Directive is that it must be required by legislative, regulatory or administrative provisions. If these condi-tions are not met, the Directive does not apply. Such voluntary plans and programmes usually arise because legislation is expressed in permissive terms, or because an authority decides to prepare a plan on an activity which is unregulated. …    3.16 Administrative provisions are formal requirements for ensuring that action is taken which are not normally made using the same procedures as would be needed for new laws and which do not necessarily have the full force of law. Some provisions of ‘soft law’ might count under this heading. Extent of formalities in its preparation and capacity to be enforced may be used as indications to determine whether a particular provision is an ‘administrative provision’ in the sense of the Directive. Administrative provisions are by definition not necessarily binding, but for the Directive to apply, plans and programmes prepared and adopted under them must be required by them, as is the case with legislative or regulatory provisions.” The footnote for the reference to “voluntary plans and programmes” in paragraph 3.15 gives as an example a legislative provision stating ‘”The authority may prepare a plan’, rather than ‘The authority shall prepare a plan’.”. 148. Paragraph 2.6 of the Government’s Practical Guide offers this advice on “administrative provisions”;    “Characteristics of “administrative provisions” are likely to be that they are publicly available, prepared in a formal way, probably involving consultation with interested parties. The adminis-trative provision must have sufficient formality such that it counts as a “provision” and it must also use language that plainly requires rather than just encourages a plan or programme to be prepared.” 149. Dealing with article 4(2) of the SEA directive, paragraphs 4.5 to 4.7 of the European Commission’s guidance on the SEA directive say this:    “4.5 In some circumstances, there may be more than one plan or programme dealing with the same broad subject matter but over a different geographical area or in different degrees of de-tail. … Article 4(3) combined with Article 5(2) and (3) is intended to ensure that duplication of assessment is avoided in this kind of situation.    4.6 If certain aspects of a plan or programme have been assessed at one stage of the planning process and the assessment of a plan or programme at a later stage of the process uses the findings of the earlier assessment, those findings must be up to date and accurate for them to be used in the new assessment. …    4.7 … Depending on the case, it might be appropriate to summarise earlier material, refer to it, or repeat it. But there is no need to repeat large amounts of data in a new context in which it is not appropriate”. 150. Paragraphs 5.11 to 5.14 of the European Commission’s guidance give advice on the evaluation of “reasonable alternatives”. Paragraph 5.12 says that “the essential tiling is that the likely significant effects of the plan or programme and the alternatives are identified, described and evaluated in a comparable way”, and that there must be “an accurate picture of what reasonable alternatives there are and why they not are considered to be the best option”. Paragraph 5.14 advises that “[the] alternatives chosen should be realistic”.                The sustainability appraisals for the development plan             151. The “Replacement London Plan Sustainability Statement”, dated July 2011, referred to the Integrated Impact Assessment Report, published in October 2009, which had concluded that the spatial development strategy was “broadly positive when considered against the sixteen IIA objectives” (paragraph 3.6). It acknowledged the possibility of “large development projects” in London having environmental effects “as a result of individual development or cumulatively alongside other developments”, and said that “localised im-pacts will also be considered through Local Development Frameworks (LDFs), Area Action Plans (AAPs), Development Briefs and through the Environmental Impact Assessment (EIA) process” (ibid.). 152. LBHF’s “Sustainability Appraisal Report for the Core Strategy Options”, dated June 2009, was used in the preparation of the submission draft of LBHF’s core strategy of January 2011. Ms McLoughlin refers to this (in paragraph 33 of her witness statement):    “The LBHF Core Strategy Options June 2009 was also subject to SA … .A convention centre proposal, housing led redevelopment and the status quo were all assessed. This assessment informed the submission Core Strategy (November 2010), which was submitted in January 2011.” 153. Section 7 contained an “Appraisal of the Spatial options”. One of the “spatial options” considered was “D: The long term strategy for the council housing estates” (paragraph 7.2). In the summary of options under “D: Council Housing Estates and Decent neighbourhoods” (preceding paragraphs 7.16 to 7.22) it was acknowledged that “[where] redevelopment is an option it could take a number of forms depending on the particular problems on the estate and the opportunities that may exist to bring forward beneficial and viable schemes”. These options were Option D1 – “Small scale development of unused land possibly with redevel-opment of a small part of an estate …”, Option D2 – “Redevelopment of a significant part of an estate … “, Option D3 – “Phased redevelopment of a whole estate over a lengthy period (e.g. up to 10-15 years) …”, and Option D4 – “Phased redevelopment of a whole estate in conjunction with development of adjacent or nearby privately owned land …” The relative benefits and disadvantages of each of these four options were dis-cussed. Paragraph 7.20 said that the core strategy “[did] not identify a preferred option” but recognized that to establish “decent neighbourhoods” it would be necessary for there to be “redevelopment across estates, the extent of which be dependent on local circumstances and the opportunities for each estate”. Option D4 was said to be the “most sustainable” (ibid.). Paragraph 7.22 indicated that the “preferred approach” in the core strategy included concentrating “major growth in five key opportunity areas”, and “redevelopment of housing estates depending on local circumstances but to decent neighbourhood principles”. 154. Section 8 appraised options for each regeneration area. For the Earl’s Court area, including the West Kensington and Gibbs Green estates, the “preferred option” was said to be “to bring together all the land in a comprehensive mixed use scheme to provide housing, employment, hotels, leisure, offices and associated facilities” (in the discussion of the “Preferred option” preceding paragraphs 8.64 to 8.68). Within this option the “preferred option for the part of the area based on West Kensington and Gibbs Green estates” was said to be “for phased redevelopment over 20 years as part of a comprehensive scheme for the whole regenera-tion area” (ibid.). Two other options were considered. “Alternative option 1” was described as “[a] compre-hensive approach but based mainly on housing without an [International Convention Centre] or a significant commercial element” (in the box preceding paragraph 8.69). And “Alternative option 2” was “[to] deal with the future of the sites separately without trying to combine the land in one overall scheme”, leaving “[the] future of the housing estates [to] be considered as a separate development scheme” (in the box preceding para-graph 8.70). 155. The “Sustainability Appraisal” for LBHF’s core strategy, dated October 2011, explained the “Sustainabil-ity Appraisal Process” for the core strategy (in paragraphs 3.8 to 3.13). In paragraphs 3.12 and 3.13 it said:    “3.12 [LBHF] made the decision to produce a second round of Core Strategy options in June 2009 to provide a clearer set of spatial options for delivery of [its] overall vision. This was done because significant alterations had been made since the June 2007 consultation. An SA report accompanied the June 2009 Core Strategy Options which again looked at preferred and alter-native options.    3.13 This SA report responds to Stage C of the SA process and relates to the appraisal of the proposed submission Core Strategy Regulation 27 document. It includes assessment carried out under Stage B of the policies that have been developed from the preferred options included in the June 2009 document.” 156. This sustainability appraisal considered the “Cumulative Effects of the Core Policies” in section 10. Paragraph 10.1 recognized that whilst a single strategic policy “might elicit a favourable sustainability com-ment, when policies are considered together the overall assessment of significant impacts may be different”. It also acknowledged that “any strategy that is based on ‘regeneration through development’ will have wider and deeper significant impacts both locally and to the wider environment”. Paragraph 10.2 said that “despite the detail and objectiveness of the SA/SEA approach now required to be applied to Local Development Plans … it will be necessary for each development … that comes forward to be assessed separately, particu-larly if it is a major scheme”. However, paragraph 10.3 concluded that “the sustainability appraisal objectives are not obviously at risk as a result of the proposed submission Core Strategy policies acting cumulatively to generate a significant negative effect”. 157. Different options for the regeneration of the Opportunity Area were also considered in RBKC’s “Sus-tainability Appraisal Report” for the proposed submission core strategy, dated October 2009. Ms McLaughlin explains what was done in that process (in paragraph 32 of her witness statement):    “The SA of the RBKC’s Core Strategy is dated [October] 2009 …. Chapter 3.4 of the SA sets out the reasons for selecting preferred strategic site allocations in the Core Strategy. Figure 4 (at para 3.4.4) illustrates when and where strategic site options were considered in the devel-opment of the plan. For the Earls Court Strategic Site, alternative options were considered in the ‘Towards Preferred Options’ document [of] July 2008. At para 3.4.24 the reasons for not selecting options for the Earls Court Strategic Site are given. The RBKC document ‘Towards Preferred Options’ identifies three options: residential led, office led, or including a convention or exhibition centre. This last option could be compatible with either of the first two. Represen-tations received to that consultation identified that the land owner had aspirations for retail on the site. But this option was then also assessed, and rejected because of its impact on existing town centres. For this reason the SA of the RBKC’s Core Strategy ([October] 2009) identifies that the options rejected at proposed submissions stage included retail and status quo.” 158. RBKC’s “Sustainability Appraisal Report” also considered the cumulative effects of development. Sec-tion 6, “Conclusions and Monitoring”, considered “Cumulative effects” in paragraph 6.1.3, and in Table 18, “Cumulative effects discussion”, which considered the “potential for cumulative effects of the Places, Strate-gic Sites and Development Management Policies in terms of each SA objective”. The report then considered, in sub-section 6.2, measures for “Mitigation and Monitoring”. In the light of the assessment set out, para-graph 6.3.6 concluded that “cumulatively the policies in the Core Strategy should lead to positive sustainable development outcomes”.                The sustainability appraisals for the SPD             159. Ms McLoughlin describes the SEA for the SPD in this way (in paragraphs 31 and 34 to 37 of her wit-ness statement):    “31. The authorities’ policies as set in the London Plan (2011), LBHF Core Strategy (2011) and RBKC Core Strategy (2010) were subject to a Full SA/SEA process and considered ‘sound’. That finding cannot now be questioned. However, [LBHF and RBKC] chose in any event to produce a sustainability appraisal of the SPD, the content of which reflected the position of the SPD in the development framework. For example, it was not open to the SPD to promote pro-posals for the Opportunity Area other than those anticipated in the Core Strategies and London Plan, and therefore there was no requirement to assess such[.]    …    34. Alternative development options, including one without estate regeneration, were consid-ered in the first draft SPD, published for consultation in March 2011. This draft SPD, including the development options, was subject to a SA/SEA ([March] 2011 …), which considered the environmental impact of these options.    35. … The March 2011 SA also included an assessment of the three development capacity scenarios.    36. The second draft SPD ([November] 2011) did not put forward development options, but a framework of ‘objectives’ and ‘key principles’ that would be used to assess planning applica-tions in the future. Because the SPD had to conform with the Core Strategies, and be in gen-eral conformity with the London Plan, the options available at the stage of drafting the SPD were limited. This SA tested the SPD objectives and key principles against the SA objectives using a hypothetical maximum development option, with development quantum below this op-tion having less of an environmental impact.    37. The London Plan Sustainability Statement (July 2011 …) (para 3.6), LBHF Core Strategy Sustainability Appraisal (October 2011) (paras 10.1 – 10.3) and RBKC Core Strategy Sustaina-bility Appraisal ([October] 2009) (Chapter 6, in particular para 6.1.3 and Tables 15, 16, 17 and 18) consider the cumulative impacts of the policies in the respective London Plan/Core Strate-gies, including the Opportunity Area, Regeneration Areas and Strategic Site policies. This ap-proach is considered sound as the SPD does not propose a different development quantum for development in the Opportunity Area. Indeed, because the SPD was required to be in conform-ity with the Core Strategies, and in general conformity with the London Plan, it was legally in-capable of promoting a different quantum of development.” 160. The “Sustainability Appraisal” for the draft SPD, dated March 2011, explained the SPD’s “overall objec-tives” in paragraph 1.1. The first of those objectives was “To establish detailed guidance on the application of policies within the London Plan and the boroughs’ Development Plan Documents (DPDs) that would be used to assess any application in the Opportunity Area”. It went on in paragraph 1.3, where it explained the ap-praisal process, to tie itself specifically to the provisions of the SEA Directive. It said that “[the] Department for Communities and Local Government has provided guidance for merging SA and SEA as a single joint appraisal, and this approach has been applied in this report. …”. Paragraph 2.1 explained “Task A1: Links to policies, plans, programmes and sustainability objectives”:    “The SPD needs to be framed in the context of international, national, regional and local policy. A review of all relevant policies, plans and programmes has recently been carried out as part of the SA process carried out by RBKC and LBHF to aid formulation of their Local Development Framework … Core Strategies. … SA is integral to the formulation of LDF Core Strategy as per the SEA Directive and Government guidance.    The review of policy, plans and programmes carried out in association with the above SAs has been reviewed and used as a basis for the baseline in this SA, although it has been expanded and updated. …”. Paragraph 2.4 on “Task A4: Developing the SA Framework” said that “… the suite of indicators chosen to track progress towards sustainability objectives have mainly been selected from those used in the SA report on the LBHF core strategy options …”. 161. The choice of the three main options chosen for assessment – the “SPD Development Scenarios” was explained in paragraph 3.2.1:    “Task B2 of the SEA directive requires the development of capacity options or ‘development scenarios’. Three development scenarios are being developed and tested covering a range of minimum and maximum thresholds for jobs, housing, open space, commercial space, retail space, open space and infrastructure (Table 7).” All three scenarios consisted of a hypothetical mix of uses. The “Housing capacity” was different in each. In Scenario 1 it was 4,000 dwellings; in Scenario 2, 6,000; and in Scenario 3, 8,000. The notes in Table 7, “Development Scenarios”, explain that the housing capacity for Scenario 1 “is new (net additional) homes”. Scenarios 2 and 3, it says, “may include redevelopment and replacement of existing dwellings in the area, such at the 746 dwellings on the West Kensington & Gibbs Green Estates that LBHF has indicated may be included”. 162. In Table 8 in section 3.3, under the heading “Task B3 & B4: Predicting and evaluating the effects”, the potential effects of development were assessed, for each of the three scenarios, against 18 objectives. In the treatment of “Mitigation Measures” in section 3.4 it was noted that the “SEA directive requires the considera-tion of mitigation measures where negative effects have been identified, along with maximising the positive effects of the SPD where possible”. The conclusion is that “[the] overall impact of implementing the SPD is predicted to be very positive in terms of sustainability” but that “further mitigation of negative impacts is re-quired in order to meet specific sustainability objectives”. Table 9 sets out the “proposed mitigation measures”. 163. The “Sustainability Appraisal” for the revised draft SPD was completed in March 2012. The non-technical summary says that the “purpose” of [the] Sustainability Appraisal … is to assess, evaluate and predict the effects of the SPD and recommend ways in which to avoid these effects and where unavoidable, mitigate them”. It says that the “[Sustainability Appraisal] runs alongside the development of the SPD”. The first “key stage”, stage A, was “Setting the context and objectives, establishing the baseline and deciding on the scope”. The second “key stage”, stage B, was “Developing and refining options and assessing effects”. There were four steps in stage B: first, “Testing the SPD objectives against the SA framework (Task B1)”; secondly, “Developing the SPD options (Task B2)”; thirdly, “Predicting and evaluating the effects of the SPD (Tasks B3 and B4)”; and fourthly, “Considering ways of mitigating adverse effects and maximising the effects of implementing the SPD (Task B5)”. 164. In section 1, the “Introduction”, the “Sustainability Appraisal process” is described as one in which sus-tainability appraisal and SEA are merged as “a single joint appraisal” (paragraph 1.3). Section 2 sets out in a series of sub-sections the tasks involved in the assessment. 165. In sub-section 3.2, the “Summary” in paragraph 3.2.1 explains what was done in “Task B2: SPD De-velopment Scenarios” as both the draft guidance and the assessment evolved:    “Task B2 of the SEA directive requires the development of capacity options or ‘development scenarios’. The previous draft SPD set out three development scenarios with the key difference between each scenario the proposed number of residential units; 4000, 6000 and 8000 for scenarios one to three respectively. The scenarios were further developed to include an indica-tive quantum for jobs, housing, open space, commercial space, retail space, open space and infrastructure, and the impacts of each scenario were tested by the earlier draft sustainability appraisal.    The revised draft SPD no longer considers development capacity scenarios and instead sets out Key Objectives and Key Principles which any comprehensive redevelopment would need to incorporate. The Key Objectives and Key Principles also provide a basis for assessment for any proposed redevelopment. For the purpose of predicting and evaluating effects, a hypothet-ical high density scenario has been tested as it represents a ‘worst case’ scenario in terms of the potential magnitude and duration of effects. As such, it is similar to the previously tested Development Capacity Scenario 3. If the Key Objectives and Key Principles provide a suitable mechanism to control the impacts of this ‘worst case’ scenario, it is extremely likely that they will control lower density development. The high density scenario tested below assumes that the entire Opportunity Area is built out, including the Gibbs Green and West Kensington Hous-ing estates, and the revised development capacity scenario figures are set out in Table 7 below …”. The “High Density Development Scenario” is then described in Table 7. The assessment is presented, again against each of the 18 “SA Objectives”, in Table 8 in sub-section 3.3. A description of the predicted effects appears in the non-technical summary    “Predicted negative impacts related principally to transport and accessibility and air quality. In relation to transport and accessibility, accessibility through the site will improve with any com-prehensive redevelopment proposals and the public transport accessibility level will increase, but there would also be increased pressure on the highway network With regard to air quality, the effects would be linked to the increase in traffic in the area, particularly vehicular traffic. The negative effects on air quality would increase with a higher density development.” In sub-section 3.4, where the mitigation measures are considered, it is concluded, again, that “[the] overall impact of implementing the SPD is predicted to be very positive in terms of sustainability” but that “further mitigation” is envisaged. The mitigation measures are described in Table 9. A summary of them is given in the non-technical summary.                The SPD             166. In chapter 1 of the SPD a summary of the “SPD Timetable and Supporting Documentation” is given. Paragraph 1.26 refers to Figure 1.5, which, it says, summarizes “the timetable and key consultation stages in the preparation of this SPD” and “shows what supporting evidence has informed its production”. It adds that the “supporting evidence documents … produced in order to inform this SPD … can be found on the three authorities’ websites and should be read alongside [the] SPD”. Each of these documents is then briefly de-scribed. The description of the Sustainability Appraisal appears in paragraph 1.27:    “SUSTAINABILITY APPRAISAL. Assesses the potential impacts of the document on a range of environmental, social and economic criteria.” Figure 1.5, “SPD timetable and supporting documentation”, is a diagram, which shows the stages in the SPD process, and the other documents and processes linked to it. The “Sustainability Appraisal” is one of four documents listed in a box with arrows pointing to three other boxes, which represent the second, third and fourth of the four stages in the SPD process – the consultation on the draft SPD in March and April 2011, the consultation on the revised draft SPD in November and December 2011, and the adoption of the SPD in March 2012. The other three documents listed in the box with the Sustainability Assessment are the Equality Impact Assessment, the Statement of Consultation and the Statement of SPD Matters.                Submissions             167. Mr Jones submitted that even if the SPD is truly a supplementary planning document and not a devel-opment plan document it is clearly subject to the provisions of the SEA directive and the SEA regulations. It is within the definition of a “plan” requiring SEA under regulation 5 of the SEA regulations. It went through a formal process of preparation and adoption, and its purpose is to provide guidance for development pro-posals in the Opportunity Area (see paragraphs 91 to 100 of Wilkie J.’s judgment in Wakil). Its implementa-tion is bound to have significant environmental effects. The officers of both LBHF and RBKC clearly believed that the SPD required SEA. A sustainability appraisal was undertaken for it, which purported to follow the process required by the SEA directive. Inexplicably, LBHF and RBKC now say that SEA was unnecessary. However, they created a legitimate expectation that the sustainability appraisal for the SPD would comply with the regime (see, for example, R. (on the application of Vieira) v Camden London Borough Council [2012] EWHC 287 (Admin)). It did not comply. First, there was no proper assessment of alternatives to the comprehensive development of the West Kensington and Gibbs Green housing estates. Secondly, there was no proper assessment of the secondary and cumulative effects of the guidance in the SPD being put into effect, in particular where it relates to the comprehensive redevelopment of the estates. And thirdly, contrary to article 9(1) of the SEA directive and regulation 16 of the SEA regulations, there was no “statement of compliance”. The sustainability appraisals for the London Plan and the core strategies were not detailed enough either for an area action plan or for a supplementary planning document. They did not contain an adequate, up to date assessment for the comprehensive redevelopment of the estates, including secondary, cumulative and indirect effects. The non-technical summary was therefore defective, because it was a sum-mary of a defective assessment. Because the sustainability appraisal for the SPD did not satisfy the re-quirements for SEA, any “statement of compliance” issued for it would have been invalid. This is not a case in which the court could properly exercise its discretion to withhold an order to quash the SPD (see Walton v Scottish Ministers [2013] P.T.S.R. 51). 168. Mr Harris, Mr Elvin and Mr Katkowski submitted that the preparation of the SPD was not “required” by any “legislative, regulatory or administrative” provision, and thus did not come within the scope of article 2(a) of the SEA directive. Voluntary plans and programmes do not require SEA The relevant statutory provisions simply empower authorities to adopt a supplementary planning document; they do not require it. The SPD reflected the strategy set for the Opportunity Area in the development plan. SEA was undertaken for the London Plan and for the core strategies. Its lawfulness was not questioned in any proceedings. However, if the SPD did require SEA the SEA carried out for it was lawful. There was substantial compliance with the requirements of the SEA directive and the SEA regulations. The inclusion of the estates in a comprehensive redevelopment had already been subject to SEA in the sustainability appraisal for LBHF’s core strategy. Al-ternatives to this were considered both there and in the sustainability assessment of March 2011 for the SPD itself. This work did not have to be done again in the sustainability appraisal of March 2012. Options outside the strategy that had already been established in the development plan would not have been legitimate al-ternatives in the SEA for the SPD (see Ouseley J.’s judgment in Heard v Broadland District Council [2012] EWHC 344 (Admin), at paragraphs 12 and 13). Cumulative and indirect effects were considered in the sus-tainability appraisals for the London Plan and core strategies. This did not have to be done again in the SEA for the SPD. The allegation that there was no “statement of compliance” is also ill founded. There is no pre-scribed format for this. The SPD itself makes clear that SEA had been carried out for it and taken into ac-count in its preparation. Any deficiency here could be corrected with a mandatory order (see R. (on the ap-plication of Richardson) v North Yorkshire County Council [2004] 1 W.L.R. 1920). But the court could properly exercise its discretion to refuse relief altogether. Mr Elvin pointed out that the Mayor would be able to put right any of the alleged defects in the SEA for the SPD before adopting it as supplementary planning guidance.                Discussion             169. The first question here is whether SEA had to be undertaken for the SPD. 170. On ground 1 of the claim I have held that the SPD is a supplementary planning document under the 2004 Act and the 2004 regulations, not an area action plan. 171. The preparation of a supplementary planning document, as defined in regulation 2(1) of the 2004 regu-lations, is not mandatory under the statutory provisions for the preparation of local development documents and development plan documents. Supplementary planning documents do not have to be prepared if a local planning authority is to discharge its obligation in section 15 of the 2004 Act to prepare and maintain a local development scheme. But if a supplementary planning document is prepared it becomes a local develop-ment document – though not a development plan document – and, as regulation 13(8) provides, it must con-form with the policies in the core strategy and in any other relevant development plan document (see para-graphs 17 and 76 above). 172. Likewise, there is no statutory requirement for the Mayor to prepare supplementary planning guidance, though he may do so under the general provisions contained in sections 30(1) and 34 of the 1999 Act. 173. As Mr Harris submitted, the exclusion of supplementary planning documents from the requirement for a sustainability appraisal, as a result of the amendment of section 19(5)(a) of the 2004 Act by section 180(5) of the 2008 Act, seems consistent with the view that Parliament does not expect supplementary planning doc-uments to be assessed under the regime for SEA 174. I also agree with Mr Harris that a supplementary planning document seems to fit the description of a “voluntary” plan or programme in paragraph 3.15 of the European Commission’s guidance (see paragraph 147 above). 175. However, in Inter-Environnement Bruxelles ASBL v. Région de Bruxelles-Capitale Case 0567/10 [2012] Env. L.R. 30 the Court of Justice of the European Union (in paragraphs 28 to 31 of its judgment) rejected the contention that the word “required” in article 2(a) of the SEA directive meant that the adoption of the plan or programme should be “compulsory in all circumstances”. It held that a plan “whose adoption is regulated by national legislative or regulatory provisions, which determine the competent authorities for adopting them and the procedure for preparing them, must be regarded as “required” within the meaning, and for the applica-tion, of [the SEA directive] and, accordingly be subject to an assessment of their environmental effects in the circumstances which it lays down”. 176. That understanding of the word “required” in article 2(a) seems to support Mr Jones’ submission that no matter whether the SPD was an area action plan – as he contended – or a supplementary planning document – as I have held – it was nonetheless a plan or programme whose adoption was “regulated” by national legis-lative or regulatory provisions, and can thus be regarded as “required” by those provisions. The fact that LBHF and RBKC chose to prepare the SPD, rather than being compelled to do so, would not affect that con-clusion. Nor did the SPD have to be required by any administrative provision. As Mr Harris said, however, the circumstances in Inter-Environnement Bruxelles were different from this case. In that case there was a provision in the relevant town and country planning code stating that each municipality in the region “shall adopt specific land use plans, either on its own initiative or within the time limit which is imposed upon it by the Government”, though it incorporated an earlier rule from which it might be inferred that there was no ob-ligation to adopt such plans (see paragraph AG8 in the Opinion of the Advocate General). 177. If one reads paragraph 31 of the court’s decision in Inter-Environnement Bruxelles as a statement of general principle, I think Mr Jones’ submission may be right. But without deciding that it is, I turn to the further and separate question that arises under article 2(a) of the SEA directive and regulation 2(1) of the SEA reg-ulations, which is whether the SPD was a plan or programme required by an “administrative” provision. That is the third kind of requirement provided for in article 2(a) of the SEA directive. 178. In HS2 Action Alliance Limited and others v Secretary of State for Transport [2013] EWCA Civ 920 it was held at first instance ([2013] EWHC 81 (Admin)) that the Government’s Command Paper of January 2012, “High Speed Rail: Investing in Britain’s Future – Decisions and Next Steps” (“the DNS”), was not a “plan or programme” that had been “required by … administrative provisions” under article 2(a) of the SEA directive, or that “set the framework for future development consent” of the project under article 3(2)(a)) (see paragraphs 60 to 73 of Ouseley J.’s judgment).The DNS had been preceded, in 2010, by a Command Paper entitled “High Speed Rail”. In their judgment (at paragraph 71) Lord Dyson M.R. and Richards L.J. said that if they had concluded that the DNS was a plan or programme that set the framework for future development consent they “would have inclined to the view that [the DNS] should properly be treated as a plan or pro-gramme “required by … administrative provisions” within the meaning of Article 2(a), adopting an appropri-ately broad and purposive interpretation of that provision”. However, they found it unnecessary to decide that point because, on the facts, they concluded that the DNS did not set the framework for future development consent. Though he disagreed with that conclusion, Sullivan L.J. agreed (in paragraphs 180 to 182 of his judgment) that the DNS was a plan or programme required by an administrative provision. In his view the Command Paper of 2010 clearly was such a provision. It was, he said, “a statement by the Government, a national authority, as to the process which it would follow in its preparation and adoption as the competent authority of the “plan or programme” (the DNS) that falls within Article 3.2(a) of the [SEA directive]”. 179. Applying a broad interpretation to the concept of requirement by an administrative provision, I think that the SPD was requited in that sense. In several places in their core strategies LBHF and RBKC announced their intention to prepare a supplementary planning document. The need for guidance in a supplementary planning document was acknowledged in policy FRA 1 and in paragraphs 7.113, 7.131 and 8.7 of LBHF’s core strategy and in paragraphs 10.4.4, 26.2.1 and 26.3.2 of RBKC’s (see paragraphs 30 and 32 to 35 above). Paragraph 7.113 of LBHF’s core strategy says that guidance on the regeneration of the Opportunity Area will be “by means of an area planning framework in the form of a Supplementary Planning Document Paragraph 7.131 says that the SPD “is testing alternative quantums of development … and will provide more detailed guidance”. Paragraph 8.7 says that the SPD “will provide more guidance on factors that will deter-mine capacity”. And paragraphs 26.2.1 and 26.3.2 of RBKC’s core strategy, respectively, look to the SPD as a means of considering the “full development capacity and exact disposition of uses across the Opportunity Area” and providing “a framework for a coordinated and phased development” in it. All of these passages in the core strategies make clear what the local planning authorities were going to do to provide detailed guid-ance supplementing the policies and provisions of the development plan, and thus finish the framework of policy and guidance within which proposals for development in the Opportunity Area would be considered. It follows that the framework of policy and guidance required the SPD if it was to be complete. The core strate-gies said as much. I think this is enough to amount to a requirement in an administrative provision within the ambit of article 2(a) of the SEA directive. 180. Did the SPD set the framework for future development consent? 181. In Walton Lord Reed said (in paragraph 17 of his judgment) said it was implicit in the first citerion in Annex II to the SEA directive – “the degree to which the plan or programme sets a framework for projects and other activities, either with regard to the location, nature, size and operating conditions or by allocating re-sources” – that “a framework can be set without the location, nature or size of projects being determined”. He referred to what the Advocate General had said in paragraphs 64 and 65 of her opinion in Terre Wallone ASBL v Region Wallone (Joined cases C105/09 and G110/09) [2010] ECR I-5611 about the “influence” a plan or programme may have on a development consent decision. 182. In the Court of Appeal’s decision in HS2 both judgments concentrated on the nature and degree of “in-fluence” that a plan or programme may have on the subsequent decision, by narrowing the discretion that the authority making the decision would otherwise enjoy. In paragraphs 53 to 55 of their judgment Lord Dy-son M.R. and Richards L.J. said:    “53. Paradigm cases of plans and programmes which set the framework for a development consent are (i) a statutory development plan with which a proposed development should gen-erally accord and (ii) a national policy statement under section 5 of the Planning Act 2008 …. That is because they prescribe relevant criteria and/or detailed rules. They set the framework for future development consent because the decision-maker is obliged to comply with them or at least to have regard to them as material considerations. They have a real legal influence even though the decision-maker has some discretion to depart from them.    54. As the Advocate General recognised in [Terre Wallonne] there are different degrees of in-fluence. …    55. We have earlier emphasised the idea that a plan or programme which sets the framework should have some legal influence on the subsequent decision. … It is something which narrows the discretion which the decision-maker would otherwise enjoy. … [In] our view, there must at least be cogent evidence that there is a real likelihood that a plan or programme will influence the decision if it is to be regarded as setting the framework There is nothing in the jurispru-dence to indicate that a mere possibility will suffice.” Sullivan L.J. agreed (in paragraph 172) that the appropriate test was the one posed by Lord Dyson M.R. and Richards L.J. in paragraph 55 of their judgment. The essential question in his view is “whether the plan or programme is in fact capable of exerting a sufficient degree of influence over the development consent for the project in question”. If so, “it will set the framework for future development consent”. The point will be fur-ther considered by the Supreme Court because the Court of Appeal granted permission to appeal on this ground, on 24 July 2013. 183. As Wilkie J. said in Wakil (in paragraph 92 of his judgment), the “obligation to undertake [SEA] is not directly linked to the characterisation of the document as a DPD as opposed to an SPD”. Rather, the ques-tion is “whether the document falls within the description in [regulation] 5 …” as a plan or programme pre-pared for town and country planning or land use and setting the framework for future development consent on relevant projects (ibid.). In that case Wilkie J. found, on the facts, that it did (see paragraphs 93 to 100 of his judgment). 184. If one asks oneself whether the SPD, together with the relevant policies of the development plan, is likely to influence decisions on proposals for development in the Opportunity Area, and is therefore to be re-garded as setting the framework for such decisions, I think there can be only one sensible answer. Plainly it is. One sees this in the passages in the core strategies to which I have referred. Mr Elvin described the SPD as an “exemplification” of the provisions of the core strategies for the Opportunity Area. But I think it is more than that. It is, and is meant to be, practical guidance for decision-making. In paragraph 1.4 it refers to the function of the “detailed guidance” that it provides on the application of development plan policy, which, it says, will be used to assess “any planning applications in the [Opportunity Area]”. The fact that the London Plan and the two core strategies had between them set the development plan strategy for the Opportunity Area, a strategy with which proposals will have to comply if they are to earn the statutory presumption of a decision made in accordance with the plan, does not displace the influence of the SPD as a material consid-eration under section 70(2) of the 1990 Act and section 38(6) of the 2004 Act. That this influence will occur is not a “mere possibility”. It is an intentional consequence of LBHF and RBKC having prepared and adopted the SPD, as guidance required by the plan. 185. In my view, therefore, the SPD is a “plan or programme” that was both “required by … administrative provisions” under article 2(a) of the SEA directive and “set the framework for future development consent” for proposals in the Opportunity Area, under article 3(2). 186. In this case SEA was undertaken both for the core strategies and for the SPD. 187. The appropriate content of an environmental report, if one has to be prepared, will depend on the place of the plan or programme in question in any hierarchy of plans and programmes to which it belongs. This is, in effect, what article 4(3) of the SEA directive provides. There is no need for assessment to be duplicated at different levels in the hierarchy. This principle is acknowledged in paragraph 4.5 of the European Commis-sion’s guidance (see paragraph 149 above). And it has been recognized by the court in this jurisdiction – for example, in R. (on the application of Howsmoor Developments Limited and others) v South Gloucestershire Council [2008] EWHC 262 (Admin), where Sir George Newman held (in paragraphs 43 to 45 of his judg-ment) that a development brief, which was an “evolutionary” stage in the plan-making process, was to be assessed on the basis that certain principles for the development of the site in question had already been established in the local plan. 188. If an authority has rejected certain alternatives at an earlier stage in a plan-making process it will not need to revisit options already assessed (see, for example, R. (on the application of Save Historic Newmar-ket Limited and others) v Forest Heath District Council [2011] EWHC 606 (Admin), in the judgment of Collins J., at paragraphs 17 and 40; and R (on the application of Heard) v Broadland District Council [2012] EWHC 344 (Admin), where Ouseley J. said this (at paragraph 67 of his judgment):    “I accept that the plan-making process permits the broad options at stage one to be reduced or closed at the next stage, so that a preferred option or group of options emerges; there may then be a variety of narrower options about how they are progressed, and that that too may lead to a chosen course which may have itself further optional forms of implementation. It is not necessary to keep open all options for the same level of detailed examination at all stages. But if what I have adumbrated is the process adopted, an outline of the reasons for the selection of the options to be taken forward for assessment at each of those stages is required, even if that is left to the final SA …” 189. In this case the preparation of the SPD followed a development plan-making process with two distinct parts: first, the designation of the Opportunity Area in the London Plan, and secondly, the drawing of the boundaries of the Opportunity Area and the formulation of strategic policies for this allocation in the two core strategies. The SPD provided guidance in support of those policies. The guidance was circumscribed by the policies. And I have concluded that it went no further than it lawfully could in a supplementary planning doc-ument. It did not generate a new strategy. It added detailed guidance to a strategy already settled. It had to conform with the core strategies, and it did. 190. Mr Harris, Mr Elvin and Mr Katkowski submitted, and I accept, that there was an adequate and lawful assessment, complying with the SEA directive and the SEA regulations, within the development plan-making process. By the time that the London Plan and the two core strategies had all been formally adopted the statutory requirements for SEA of the development plan strategy for the Opportunity Area had been met. That assessment was done when it had to be done, during the preparation of the development plan. 191. The London Plan and the core strategies emerged unchallenged from their respective processes. In the SEA undertaken for the preparation of the development plan both alternatives and secondary and cumulative effects were considered. It is now far too late to suggest, and I do not believe Mr Jones did, that in either of those respects, or in any other respect, the SEA undertaken in the course of the plan-making process was inadequate or unlawful. And in any event I could not accept that the information and assessment presented in the sustainability appraisals for the core strategies fell short of what was reasonably required by way of SEA for those development plan documents. It included an explanation of the authorities’ strategy for the Opportunity Area in the light of alternatives they had considered, and it took account of likely secondary and cumulative effects. All of the matters referred to in Schedule 2 to the SEA regulations were covered in suffi-cient depth for an assessment at the strategic level. I think this was enough to fulfil the requirement for SEA in the process by which the development plan strategy for development in the Opportunity Area was set. 192. That is the context in which one must judge the adequacy and lawfulness of the SEA undertaken for the SPD. 193. In my view the SEA conducted for the SPD was an adequate and lawful assessment sufficient to com-plement the SEA undertaken for the London Plan and the core strategies. I accept the submission of Mr Har-ris, Mr Elvin and Mr Katkowski that in the sustainability appraisals prepared for the draft SPD in March 2011 and for the final version of the SPD a year later in March 2012 the requirements of the SEA directive and the SEA regulations were, in substance, fully complied with. “Substantial compliance” with the requirements of the SEA directive is sufficient (see Commission of the European Communities v Federal Republic of Ger-many (Case G431/92) [1995] ECR I-2189; and R (on the application of Edwards) v Environment Agency [2008] Env. L.R. 34). 194. In the process in which the SPD was prepared there was neither any legal requirement nor any justifica-tion for a duplication of the assessment already undertaken in the SEA for the core strategies. This case is a good example of article 4(3) of the SEA directive being put into practice. The strategy for the Opportunity Area had evolved in the development plan process, and the SEA had assessed it as it took shape. Alterna-tives had been considered and assessed in the sustainability appraisals prepared for the core strategies. It would have been inappropriate for the SPD to introduce new or different options that had not been ventilated during the plan-making process itself. The SPD did not add to the options already considered during the plan-making process. Nor did it favour an option previously rejected. The SEA undertaken for it did not need to repeat the work done in the SEA for the core strategies or reiterate the description of that assessment. The same applies to the local planning authorities’ consideration of cumulative effects. 195. This is not one of those cases in which the court could properly intervene on Wednesbury grounds be-cause issues of fact or judgment have been mishandled by an authority conducting SEA (see paragraph 26 of Weatherup J.’s judgment in Seaport Investments Limited, Re application for judicial review [2008] Env. L.R. 23, and paragraphs 73 to 78 of the judgment of Beatson J., as he then was, judgment in Shadwell Es-tates Limited v Breckland District Council [2013] EWHC 12 (Admin)). As the final stages of the sequence of SEA undertaken for the core strategies and the SPD, the sustainability appraisals of March 2011 and March 2012 seem to me to be beyond criticism in a claim for judicial review. 196. The sustainability appraisal of June 2009 had considered several options for the regeneration of the Opportunity Area, including the redevelopment of the estates, and had identified the most sustainable option (see paragraphs 153 and 154 above). The March 2011 sustainability appraisal for the draft SPD explained, in paragraph 3.2.1 and Table 7, the three options that had been chosen for assessment at that stage. One of the options did not involve the redevelopment of the West Kensington and Gibbs Green estates. The predic-tion and evaluation of effects in Table 8 encompassed different scenarios for development, including and excluding the redevelopment of the estates. The assessment, using the 18 sustainability objectives, was systematic and comprehensive (see paragraphs 160 to 162 above). In the March 2012 sustainability ap-praisal paragraph 3.2.1 explained how this last stage of the SEA process related to the assessment that had already been done. The basis for assessment was, in my view, sufficient and sound. It was underpinned by the SEA undertaken for the development plan and for the draft SPD. It was not deficient in its consideration of alternatives. Further assessment of an option excluding the housing estates from the comprehensive re-development of the Opportunity Area was unnecessary at this stage. That had been considered in the sus-tainability appraisal of March 2011, as Scenario 1. The prediction and evaluation of effects, in paragraph 3.3 and Table 8, was no less systematic and comprehensive than that in the March 2011 sustainability appraisal (see paragraph 165 above). The sequence and style of assessment seem to me to comply with the Europe-an Commission’s guidance (see paragraphs 147 to 149 above). 197. The submissions made for the claimants about the alleged inadequacy of the assessment of cumulative effects “in conjunction with other developments and regeneration schemes in the area” – as it was put in paragraph 102 of Mr Jones’ skeleton argument, do not go beyond assertion. In my view they do not have any substance. And I see nothing in them as a criticism of the sustainability appraisals for the SPD. The sustain-ability appraisal of October 2011 for LBHF’s core strategy had dealt with cumulative effects, in particular in paragraphs 10.1 to 10.3 (see paragraph 156 above). So had the sustainability appraisal of October 2009 for RBKC’s core strategy, in particular in paragraph 6.1.3 and Table 18 (see paragraph 158 above). The claim-ants have not demonstrated any need for further assessment of cumulative effects in the SEA for the SPD. 198. The SEA in the sustainability appraisals for the SPD, including the non-technical summary in each, was, I believe, a lawful assessment. In my view, as a continuation of the SEA for the core strategies, it was com-plete, clear, sufficiently detailed and up to date. It was adequate given the status of the SPD as guidance supplementary to the development plan and the stage in the whole process at which SEA for the SPD came to be carried out. 199. One must not forget, of course, that any major proposals for the Opportunity Area will almost certainly constitute EIA development under the EIA directive and will thus be subject to the statutory requirements governing the assessment of the likely significant effects of such projects, including any relevant cumulative effects. 200. I turn next to Mr Jones’ submission that the local planning authorities failed to provide a statement of compliance, as required by article 9(1) of the SEA directive and regulation 16 of the SEA regulations. 201. As Mr Harris submitted, the requisite information does not have to be given in any particular way. Reg-ulation 16 does not stipulate in what form the statement containing “the particulars specified in paragraph (4)” – the so-called “statement of compliance” – must be issued. How much latitude the authority has may be moot, but I think there clearly is some. 202. In this case the point raised by Mr Jones on the statement of compliance can only be an attack on the SPD and the SEA pertaining to it. The core strategies themselves and the London Plan are invulnerable; the time for any claim to be made against them was gone long ago. 203. Mr Harris pointed to paragraphs 1.26 and 1.27 and Figure 1.5 of the SPD, and sought to rely on the sustainability appraisal of March 2012 itself as a source of at least some of the information referred to in reg-ulation 16(4) of the SEA regulations. Anyone who wanted to understand, for example, “how environmental considerations [had] been integrated into the plan or programme” (paragraph (4) (a)) or “how the environ-mental report [had] been taken into account” (paragraph (4)(b)) would have to go to the sustainability ap-praisal to discover what had been done in the assessment of environmental effects and how this work had been used in completing the framework for decision-making on proposals in the Opportunity Area. 204. That is not, in my view, an adequate approach to the statutory requirements. One might be able to glean all of the information to which regulation 16(4) refers by reading the SPD and the sustainability ap-praisal of March 2012, though I was not invited to try. Even if this is possible, however, I cannot imagine that it is what the draftsmen of regulation 16 had in mind. I do not think the requirements of regulation 16 are hard to comply with. They would have been met by a single, compendious statement gathering all of the particu-lars specified in paragraph (4), cross-referenced to the relevant material. But no such statement has yet been produced. 205. I must therefore consider whether this defect in the SEA process for the SPD should lead to an order to quash. I do not believe it should. Submissions on discretion were made on both sides. In my view those made by Mr Harris, Mr Elvin and Mr Katkowski must prevail. 206. The relevant principles are clear from the Supreme Court’s decision in Walton, which clarified the juris-prudence on discretion flowing from the decision of the House of Lords in Berkeley v Secretary of State for the Environment [2011] 2 AC. 603. In Walton Lord Carnwath said (in paragraph 139 of his judgment) that where the court is satisfied that, in practice, the rights conferred by the European legislation have been en-joyed, and where a procedural challenge would fail under domestic law because the breach has caused no substantial prejudice, he could see “nothing in principle or authority to require the courts to adopt a different approach merely because the procedural requirement arises from a European rather than a domestic source” (see also Lord Hope’s judgment at paragraph 156). 207. If, as I believe, there was a breach of article 9 of the SEA directive and regulation 16 of the SEA regula-tions in this case, I do not accept that the jurisprudence on discretion points towards an order to quash the SPD. The remedy need go no further than the kind of relief contemplated by the Court of Appeal in R. (on the application of Richardson) v North Yorkshire County Council [2003] EWCA Civ 1860. In that case there had been a breach of regulation 21(1) of the Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 1999, which required the authority granting permission to make available for public inspection a statement containing the main reasons and considerations on which its decision was based. In paragraph 38 of his judgment Simon Brown L.J., as he then was, referred to what Richards J., as he then was, had said at first instance: that regulation 21(1) “looks to the position after the grant of planning permission” and is “concerned with making information available to the public as to what has been decided and why it has been decided, rather than laying down requirements for the decision-making process itself. He accepted that in such circumstances the court was not compelled to quash the planning permission; a mandatory order would suffice (see paragraphs 33 and 38 of his judgment). 208. The same essential reasoning, now strengthened by the Supreme Court’s decision in Walton, applies in this case too. The error I have found was one of omission in the procedure followed after the adoption of the SPD. It did not infect either the process in which the SPD was prepared or that in which the SEA for it was carried out. It could readily be put right, without either process having to be rerun, by a mandatory order re-quiring LBHF and RBKC to issue a statement that meets the requirements of regulation 16. And, as Mr Elvin said, the Mayor could do that anyway if, as he intends, he adopts the SPD as supplementary planning guid-ance. I do not think the claimants have suffered any real prejudice as a result of the authorities’ failure to pro-vide a statement complying with regulation 16. Nor has anyone else. Certainly, there is no prejudice that could not be wholly overcome by a suitable statement being issued at this stage. The requirements of the SEA directive and the SEA regulations for the preparation of an environmental report and for public consulta-tion have been complied with, not only in the development plan-making process but also in the preparation of the SPD. The claimants were able to participate in those processes. 209. In these circumstances I can see no justification for the draconian step of quashing the SPD. A manda-tory order, however, is appropriate, requiring LBHF and RBKC to publish a statement of the matters referred to in regulation 16(4). The submissions on delay made by the parties opposing the claim – which at this stage went only to discretion – do not dissuade me from taking that course.                Conclusion             210. For the reasons I have given the claim succeeds only to the extent that a mandatory order will be made requiring LBHF and RBKC to issue a statement complying with the requirements of regulation 16 of the SEA regulations. I shall hear counsel on the appropriate form of relief.