Rooftop extensions to residential buildings are becoming increasingly popular. Since the government introduced permitted development rights in August 2020, most developments of this type will not require planning permission.
However, where planning permission is required, it is sometimes not plain sailing. Issues relating to design, the structural integrity of the existing building and the need to decant existing residents are common themes. These were the issues before the High Court in the recent case of Vanbrugh Court Residents’ Association v Lambeth London Borough Council [2022] EWHC 1207 (Admin); [2022] PLSCS 82.
The facts
The developer applied for a roof-level extension to a four-storey block of flats in Lambeth to provide 16 additional residential units and five external lifts. The developer needed to apply for planning permission because the law granting PDRs for such upwards extensions to residential buildings had not yet come into force.
The residents of the building objected to the planning application. Their main concern related to the structural feasibility of the building to support the additional roof level. They argued that this was a material consideration for the local planning authority when determining the application. There was no evidence before the LPA assessing whether the existing building could support the upwards extension, and they contended that the developer should have been required to provide a structural survey to the LPA to address the issue. Related to that, they were also concerned that they may need to vacate their flats during construction, which should have also been a material consideration for the LPA.
The London Borough of Lambeth granted planning permission and the residents applied for judicial review.
Structural feasibility
The court held that the structural integrity of the proposal fell under the building control regime and the LPA was able to place reliance on the effective operation of that regime. Although the point was not specifically argued by the parties, the judge noted that, had PDRs been available at that time, there would have been no requirement to submit structural information in relation to prior approval applications for such development.
Risk of residents needing to vacate
With regard to the vacation of homes during construction and whether that was a material planning consideration, the residents argued that the LPA had not taken this into account at all, which was unlawful. Conversely, the LPA contended that it accepted that this issue was a material consideration but chose to give it no weight, which it was entitled to do.
The court agreed with the LPA. The LPA’s officers had engaged with the issue of whether residents needed to vacate and had relied on the developer’s advice that the need for residents to decant would be highly unlikely. This assessment corresponded with the professional experiences of officers. In summary, the court held that the LPA treated the question of whether residents might have to vacate their homes as being legally capable of a material consideration but chose to give it no weight on the evidence before it. The court held that the decision to attach no weight to the issue could not be described as irrational and was therefore not unlawful.
Design
There was a debate about the interpretation of the National Planning Policy Framework, in which paragraph 120 requires upwards extensions to be “well designed”. The residents argued that this refers not just to the external appearance of upwards extensions but also to their structural design. The court disagreed with that interpretation. Design in NPPF terms is distinct from structural integrity, which is left to the building control regime.
What this case tells us
On one level, the case narrows down the likely issues a developer will need to address if it has to submit a planning application. More importantly, the case is a helpful reiteration of the law on two common topics. First, overlapping consenting regimes – LPAs are entitled to rely on other regulatory regimes (here the building control regime) to do their job. However, the LPA still needs to deal with the issue in question – it must be able to satisfy itself that the other regulatory regime is capable of regulating the relevant issues.
Secondly, the case is also a reminder of the law relating to the often litigious topic of material planning considerations. The law says planning applications must be determined in accordance with the development plan unless material considerations indicate otherwise. There is no statutory definition of what constitutes a material consideration. LPAs may decide whether a factor is a material consideration. The LPA would only be acting unlawfully if a consideration is so obviously material that to not take it into account would be irrational. There was no need for the court to make a decision on this issue as it agreed with the LPA that it had in fact taken into account the potential need for the residents to vacate as a material consideration.
Once an LPA accepts that a factor is a material consideration, it is up to the LPA to decide what weight to give it, provided it acts rationally. In this case, the court held that the residents’ challenge was, in effect, to the weight attached by officers to the issue of the need to decant. The court reaffirmed that the question of weight is not a matter for the court.
Claire Dutch is a partner and co-head of the planning and environmental team at Ashurst LLP
