Lord Justice Tomlinson :
1. The Claimants, Mr and Mrs Stanley, and the Defendants, Mr and Mrs Rawlinson, are neighbours in Mistley in
2. Whatever may have been the difficulty of seeing over the wall before that date, after the collapse of the wall the
3. It would seem that in 2001 the Stanleys and the Rawlinsons enjoyed a good if not close neighbourly relationship but for whatever reason that deteriorated over the course of the next few years. In September 2007 the Rawlinsons received from the Stanleys’ solicitors a letter which asserted that the wall had collapsed as a result of their having piled up against it a large quantity of earth which derived from the excavation of a swimming pool on the Rawlinsons’ property. It is said by the
4. Both sides commissioned expert evidence, those experts being predictably hampered by their coming to the task so long after the collapse of the wall. Thus Mr Croucher for the Claimants carried out his first inspection in June 2008, nearly seven years after collapse of the wall. There were various interlocutory skirmishes in the action. The matter ultimately came on for trial in early December 2009 before His Honour Judge Moloney QC in the Chelmsford County Court. The trial lasted for three days, one day longer than estimated. Both sides were represented at trial by counsel. It was common ground at the trial that the immediate cause of the collapse of the wall was the high wind in the night, but the Claimants contended that the wall had been rendered more vulnerable to collapse than already it was by reason of work then in progress on the Defendants’ side of the wall. It was in dispute whether any such works had been in progress at the relevant time and, if so, of what they consisted.
5. The judge found that there were works in progress at the time, but not of the nature contended for by the Claimants. In particular, the relatively modest groundwork carried out adjacent to the wall by hand tools, not heavy machinery, involved no piling up of earth against the wall and no compaction of the material adjacent to the wall. The judge found that “the works actually carried out before 7 October 2001 are not likely to have had any material effect on the ability of the wall to resist wind pressure”. The judge concluded:-
“. . . those works were so minor in nature, as far as any contact with the wall or disturbance of the adjacent soil is concerned, that the Claimants have failed to persuade me on the balance of probability that the works led to any increase in the pressure or other forces exerted on the wall by the Defendants’ land or activities. From this it must follow that the condition of the wall was not materially affected by the works, that its collapse was probably due to other causes, in particular the combination of high winds with its pre-existent age and condition.”
In the light of the history I have recounted this is perhaps an unsurprising conclusion.
6. In this court Mr and Mrs Stanley were represented by Mr James Newman, instructed by the Bar Pro Bono Unit. We are very grateful to Mr Newman for his assistance. Although I shall deal in more detail with his submissions hereafter, he was constrained to accept that his case amounted to no more than the proposition that because the wall had apparently in the relatively recent past, notably on 13 December 2000, survived a wind of apparently greater strength and because in October 2001 there was some work in progress on the Defendants’ side of the wall, the only principled conclusion which the judge could have reached was that the work being carried out caused the wall to collapse. That proposition is self-evidently unsustainable. The appeal to this court was I am afraid quite hopeless. To have become embroiled in this litigation is I have no doubt a disaster for both the Stanleys and the Rawlinsons, to be measured not just in financial terms. However I cannot forbear to observe that the wall could have been rebuilt six times over with the money apparently expended in fighting this case, and moreover could have been rebuilt nine years ago and enjoyed in the interim.
7. One apparent reason why the litigation has reached this court is a belief on the part of the
8. One is entitled to observe that ordinarily one might have expected that the Rawlinsons would remember whether the collapse of the wall occurred before or after they had been conducting work immediately adjacent to it, and that of course had led the
9. The judge resolved the issue of the timing of the works by reference to photographs which the
10. The judge observed that there had been accusations of bad faith going both ways, but proceeded upon the basis that each side had had to do its best to reconstruct the situation from limited data and that there must inevitably have been room for hindsight and wishful thinking.
11. The photographs were however a two-edged sword in the hands of the Claimants. On the one hand they demonstrated that some work had been in progress at the relevant time. On the other hand they also demonstrated that that work did not consist of piling up earth against the boundary wall, did not involve the importation and laying of fill material against the wall and moreover that no compaction of the ground or the material adjacent to the wall had by the time of its collapse occurred. The assumptions on the basis of which Mr Croucher for the Claimants had given it as his opinion that the work on the Rawlinsons’ side had led to the collapse of the wall were thereby destroyed.
12. The judge’s essential findings of fact are set out in paragraphs 7 and 8 of his judgment, which I reproduce below in full:-
“7. As to the prior condition of the wall, there was a substantial measure of agreement between them. Both now accept:
a. that the wall is brick-built and is of considerable age, probably mid 19th century;
b. That prior to its collapse it had for some years shown a perceptible lean towards the Claimants’ property (some 80mm. on a height of about 1.50 metres according to Mr Leeds);
c. That that lean was probably (Mr Leeds) or possibly (Mr Croucher) the consequence of the action of tree roots over a long period, there being a fig tree on the Claimants’ side and two Scots pines on the Defendants’ side in fairly close proximity to the collapsed section of the wall;
d. That the greater the lean in a wall, the more vulnerable it is to wind pressure in the direction of the lean;
e. That although at the time of construction the ground levels may have been much the same on both sides of the wall (it was not specifically constructed as a retaining wall) for many years prior to the commencement of the works the ground level on the Defendants’ side had been appreciably higher than on the Claimants’; the experts’ plans and trial pits show a difference in height above ground level of some 6 courses of brick or 500mm, though the difference varied somewhat along the length of the wall, and old photographs indicate that the situation has not changed much since at least the 1980s.
8. As to the nature and extent of the works at the time of the collapse, much of the experts’ previous research has been rendered redundant by the production of the contemporary photographs referred to above and the evidence of Mrs Rawlinson as to the course the works took (which the Claimants were not in a position effectively to challenge). In summary she told me that the kitchen and outbuilding works were dealt with first, and the resurfacing left till last; this is consistent with the photographs which show those building jobs substantially complete. As to the resurfacing, the first step was to break up and lift the old concrete on part of the back yard; this was not done mechanically but by hand with pickaxe and spade. The resulting earth, broken concrete and brick was then spread, again by hand, over the whole yard in such a way as to level off the previous slight slope or gradient. This hardcore was then compacted and levelled by hand with shovels; hoggin was laid on top, and finally a layer of shingle. I accept this account. In the light of the photographs and my finding as to their date, it follows that the wall fell at the time just after the hardcore had been spread over the whole areas, but immediately before it had been compacted, since the photographs clearly show it in an irregular uncompacted state. At this stage, before compaction, the height of soil against the wall on the Rawlinson’s side may have been raised by a small amount, particularly where the former gradient had been levelled up; subsequently, after compaction, the height is little different from its original level.”
13. The judge then posed what he described as the crucial question, “What if any effect the breaking-up of the surface layer and its distribution as described, but without any compaction, would have had on the ability of the wall to resist high winds? He recited that on this issue the Claimants’ case had gone through several changes:-
“i. Originally they were under the false impression that the works had involved the Defendants bringing large quantities of soil onto the yard from elsewhere, heaping it high against the wall, and compacting it, perhaps mechanically. (If so, it is plainly likely that there would have been an increase, perhaps a substantial one, in the forces transmitted from the Defendants’ land to the Claimants’ wall, whether by means of the weight of the soil, the forces associated with its compaction, or the pressure of water contained within or accumulated in it, and one can well see how such forces applied to an already leaning wall might have caused it to tilt further and increased its vulnerability to wind pressure.)
ii. Upon it becoming clear that no such new soil had been brought on to the site, the weight point lost force, but Mr Croucher’s last opinion before trial was that a similar result would follow from “the sideways pressures which result from compaction of the ground to consolidate it, together with rainwater getting into the soil against the wall”.
iii. At trial it became clear that there had been no compaction either before the wall fell, but Mr Croucher valiantly maintained that nevertheless the breaking up of the concrete and the disturbance of the soil would have reduced the binding effect within the soil, and increased its tendency to absorb water, thus increasing the hydrostatic pressure against the wall and the soil’s ability to transmit surface loads.”
14. The view of Mr Leeds, who gave expert evidence for the Defendants, was:-
“ that the presence of uncompacted soil, as seen in the photographs, could not cause the wall to collapse; as to the question of trapped water and its effects, he said that while the presence of such water over a long period might have an effect on a wall, here the soil was sandy and granular with no clay base and the rainwater would easily drain away. His overall view was that this was an old wall which had already become very vulnerable. If the works had exerted any appreciable forces on the wall, it would have fallen even before the high winds; as it was the wind alone was a sufficient explanation.” (Judgment paragraph 10)
15. At paragraph 11 of his judgment the judge referred to what he described as a new point first raised in oral evidence by Mr Croucher, which had at first given the judge serious concern, namely that the meterological evidence from a nearby weather station showed that although the wind speed on 6/7 October 2001 had been high, there had been many occasions in the previous few years when it had been a good deal higher; since wind pressure increases with the square of wind speed, why had the wall not fallen before, unless its strength had been reduced by some recent event? However the concerns of the judge on this point were evidently allayed by Mr Leeds, who as the judge recites:-
“pointed out that it not only the speed of the wind, but its direction and the effect of local topography, which determines its effect on particular buildings, so that a mere record of wind speed in another location is of little or no evidential value as to the forces previously exerted on this wall. (As stated at 7(d) above, the experts are agreed that the direction of the wind is highly material to its effect on the wall.)” (Judgment paragraph 11)
16. At paragraph 12 the judge set out his comparative evaluation of the two experts in these terms:-
“Mr Croucher’s academic and professional qualifications are a good deal higher than Mr Leeds’s, but both are men with more than 30 years’ experience in structural engineering and design. Mr Leeds gave his evidence before me in a frank and clear manner, and stated his opinions without apparent regard for their likely effect on the Defendants’ case. As I have indicated, Mr Croucher’s conclusions remained favourable to the Claimants notwithstanding adverse developments in the evidence. Also, I was shown correspondence between him and the Claimants in which he appeared to go beyond the usual role of an expert witness by advising them on the evidence they needed to meet the opposing case; when taxed on this in cross-examination he maintained that he owed a dual duty to the Court and to his “client”. When choosing between the two, I would generally therefore favour Mr Leeds’s evidence, all else being equal.”
The judge then expressed his conclusion to which I have already referred at paragraph 5 above, adding that his assessment that the works were minor in nature as far as any contact with the wall or disturbance of the adjacent soil is concerned was informed by the views of both experts.
17. Mr Newman submitted that the judge was unfair to Mr Croucher in failing to recognise that the “rainwater theory” had always been a part of his essential thesis. It is true that in his first report Mr Croucher referred to water pressures occurring due to the absence of weep holes in the wall, though this was in the context of the level of the ground on the Rawlinsons’ side having been raised by filling and by compacting of the fill behind the wall. It is also true that in his second report of 21 July 2009, commenting on Mr Leeds’ first report, Mr Croucher referred again to the “sideways pressures which result from compaction of the ground to consolidate it, together with rainwater getting into the soil against the wall, . . . [giving] rise to higher than normally experienced pressures against the wall, which can cause it to lean over.” Self-evidently however, none of this was in the context of work consisting of no more than the breaking up of the concrete layer and spreading of earth, brick and broken concrete with no compaction. The judge was in my view justified in approaching Mr Croucher’s evidence on the basis that what had hitherto been a phenomenon associated with compaction of the ground had now been elevated to a theory requiring no more than disturbance of the soil to give rise to significantly increased hydrostatic pressure against the wall.
18. To be fair to Mr Croucher, when he first put forward this theory in his examination in chief he did not attribute to it overwhelming significance. He described how removal of the concrete would render the ground susceptible to rain penetration and how the water lubrication of the soil would reduce inter-granular friction making it more susceptible to disturbing forces and transmission of surface loads but concluded:-
“Now, the extent to which that takes place I can’t say. It’s very easy to over-egg the pudding, but it is nevertheless, I think, a consideration.”
19. I also consider that the judge was unduly critical of Mr Croucher in characterising an email of 16 April 2009 sent by him to Mr Stanley and copied to Mr Stanley’s solicitor as appearing “to go beyond the usual role of an expert witness by advising them on the evidence they needed to meet the opposing case.” The judge was also impliedly critical of Mr Croucher’s response to being taxed with this document in cross-examination to the effect that he owed a dual duty to the court and to his “client”, the parentheses being those of the judge. Mr Croucher was quite right to observe that he owed a duty to his client as well as to the court. This is inherent in CPR 35.3 which provides:-
“35.3(1) It is the duty of experts to help the court on matters within their expertise.
(2) This duty overrides any obligation to the person from whom experts have received instructions or by whom they are paid.”
Practice Direction 35 at paragraph 4.1 explains how experts must approach their task when giving or preparing evidence for the purpose of proceedings:-
“4.1 Experts always owe a duty to exercise reasonable skill and care to those instructing them, and to comply with any relevant code of ethics. However when they are instructed to give or prepare evidence for the purpose of civil proceedings in England and Wales they have an overriding duty to help the court on matters within their expertise (CPR 35.3). This duty overrides any obligation to the person instructing or paying them. Experts must not serve the exclusive interest of those who retain them.”
Experts are often involved in the investigation and preparation of a case from an early stage. There is nothing inherently objectionable, improper or inappropriate about an expert advising his client on the evidence needed to meet the opposing case, indeed it is often likely to be the professional duty of an expert to proffer just such advice. The opinion of an expert is often if not usually dependent upon the precise nature of a factual situation which he must to some extent assume to have existed. There is nothing improper in pointing out to a client that his case would be improved if certain assumed features of an incident can be shown not in fact to have occurred, or if conversely features assumed to have been absent can in fact be shown to have been present. The judge’s criticism of Mr Croucher was in my view in this respect misplaced. More pertinently however Mr Croucher did observe in his email “We need to be very careful to avoid putting too much emphasis on the treatment of the ground on Mr and Mrs Rawlinson’s side prior to the collapse of the wall.” That cautious approach foreshadows that which he adopted when introducing the rainwater theory in his examination in chief.
20. The rainwater theory was never likely to carry the day. Mr Croucher noted in his first report that the subsoil type was not of a nature that was susceptible to slow volume change when taking up or expelling water. The subsoil exposed in the trial pit was predominantly sand and conditions were not believed to vary significantly across the plot. There was no standing ground water in the trial pit. The rainfall overnight on 6/7 October was not out of the ordinary and had been negligible in the previous three days. Furthermore Mr Croucher had also commented in his first report on the stability of the south-eastern boundary wall of the two properties, a wall which had shown movement over the years but which did not collapse on the night of 6/7 October as did the south-western wall. In relation to the former wall Mr Croucher gave it as his opinion:-
“Water pressures on the retained sides of the walls and their foundations below ground level are unlikely to occur due to the topography and nature of the subsoil.”
In answers given to the judge and in cross-examination Mr Croucher gave no satisfactory explanation as why the same was not equally true of the south-western wall. Indeed he appears to have accepted that the only reason for not in his report treating the significance of hydrostatic pressure on an equal footing for both walls was his assumption, subsequently falsified, that the resurfacing works involved raising the ground level on the Rawlinsons’ side.
21. The judge made clear at paragraph 13 of his judgment that his “main reason” for his conclusion that the works carried out before 7 October are not likely to have had any material effect on the ability of the wall to withstand wind pressure was not the poor view he formed of Mr Croucher’s evidence but rather the insubstantial nature of the work so far as concerns contact with the wall or disturbance of the soil. Mr Newman submitted that if the judge had approached Mr Croucher’s evidence in a more generous spirit, recognising the difficulties in which he had been placed before trial by the uncertain state of the evidence, a matter beyond his control, and without unfair criticism of his objectivity, he would necessarily have accepted the “rainwater theory” as explaining why the wall collapsed on this occasion. I am afraid that I cannot accept that submission. In my view it would have been very surprising if the judge had reached that conclusion. His finding that the Claimants could not show on the balance of probability that the works led to any increase in the pressure or any other forces exerted on the wall seems to me both principled and right. The removal of the concrete which had lain over part of the ground adjacent to the wall and the disturbance of the soil could be at best “a consideration”. I also reject Mr Newman’s criticism that the judge was not entitled to regard the views of the experts as informing his own view that the works were in the relevant respect minor in nature. Mr Leeds did not describe the groundwork carried out prior to 7 October as “a fairly significantly amount of work”. His use of that expression was plainly descriptive of the entire programme of works undertaken by the Rawlinsons as set out at paragraph 8 of the judge’s judgment.
22. Mr Newman was also critical of the judge’s acceptance of Mr Leeds’ evidence as to the significance of local topography in influencing the effect of wind on structures and as to the limited value of evidence as to wind speeds recorded at another location when assessing the pressures previously exerted on this wall. In that regard the Claimants introduced into the trial bundle a few days before trial a record of dates on which, in the years between 1987 and 2001, a maximum gust speed equal to or greater than 49 mph had been measured at the Wattisham Meteorological Station. The significance of 49 mph is that the General Monthly Survey for Wattisham for October 2001 recorded the maximum gust speed on 7 October as 49.5 mph.[1] The maximum recorded for 6 October was 29.9 mph. It was this evidence which gave rise to the point raised by Mr Croucher at trial as to the significance of the wall not having previously collapsed despite higher wind speeds having been measured at the weather station. Wattisham is approximately twenty miles distant from Mistley.
23. I am a little surprised at this criticism of the judge as it seems to me that both Mr Croucher and Mr Leeds gave evidence broadly to the effect that the measurement of wind speed at a station remote from the site cannot be regarded as necessarily typical of the wind speed at a wall within a cluster of buildings in an urban (or at any rate a built-up) area. That would also seem to me common sense, derived from the common experience that the effect of wind can be very localised. Likewise I do not find very persuasive an argument to the effect that because an old, leaning and poorly maintained wall had not fallen down in high winds in the previous fourteen years so then on this occasion some minor works in the area adjacent to it must necessarily have made all the difference.
24. The Claimants have gone so far as to seek permission to introduce fresh evidence on this point, evidence which they accept would, if admitted, and if it shows the judge’s approach to have been flawed, necessitate a retrial. The evidence in question is a report of Dr Stephen Dorling, a Chartered Meteorologist. However, far from showing that Mr Leeds was wrong, Dr Dorling confirms that “the precise weather conditions experienced at a particular location are always affected by local topography”. He goes on:-
“However, in order for insurance companies to be able to address the validity of a weather-related claim in a practical, timely and fair way, weather conditions at the closest neighbouring reporting stations are used to inform their response. This is the practice across the insurance industry and the approach is recognised by the Financial Ombudsman . . .”
This industry practice is no doubt a practical initial approach to claims handling, but it does not assist here and it does not detract from the accuracy of Mr Leeds’ evidence on the point. I cannot therefore accept Mr Newman’s submission that the evidence contained in the report of Dr Dorling could have had an important influence on the trial because it challenges the evidence given by Mr Leeds. It follows that on that ground alone I would not admit the fresh evidence. It is unnecessary to consider to what extent the traditional Ladd v
25. In my judgment there is nothing in the point that the wall had apparently withstood higher winds on earlier occasions.
26. Since I would not disturb the judge’s findings, it follows that Mr Newman’s last point, to the effect that the judge may have misunderstood and misapplied the decision in Dalton v Angus [1881] 6 App Cas 740 concerning the easement of support does not arise.
27. I would dismiss this appeal.
Mrs Justice Baron
28. I agree.
Lord Justice Laws
29. I also agree.
[1] In the light of the more detailed report of Dr Dorling to which I refer below, it may be a moot point whether a gust of that magnitude was recorded overnight 6/7 October as opposed to later in the day on 7 October. The trial was conducted on the agreed basis that there were high winds in the night and that this was the immediate cause of the collapse.
