Case No: CO/5017/2015 
Neutral Citation Number: [2016] EWHC 1978 (Admin)
IN THE HIGH COURT OF JUSTICE
QUEEN'S BENCH DIVISION
PLANNING COURT

Royal Courts of Justice
Strand, London, WC2A 2LL

Date: 09/09/2016

Before :

MR JUSTICE GILBART

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Between :

	THE QUEEN
on the application of JUDITH WATT	Claimant	
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	LONDON BOROUGH OF HACKNEY
and
ZOE CHAN	Defendant

Interested Party	

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Christopher Jacobs (instructed by Dowse and Co, Solicitors of Dalston) for the Claimant
Giles Atkinson (instructed by Director of Legal and Democratic Services, London Borough of Hackney) for the Defendant
The Interested party did not appear and was not represented

Hearing dates: 27th April 2016, 23rd June 2016

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Judgment
GILBART J : 
1.	This is an application to quash the resolution of the London Borough of Hackney (“LBH”) of 2nd September 2015 to grant planning permission for the erection of a three storey building comprising a café (Class A3) use at basement and ground floor level, and two one bedroom flats (Class C3) at first and second floor, with associated cycle parking. It is to be noted that the original application for permission had included another residential unit, and was for a building of four storeys.
2.	As will become apparent, this challenge by the Claimant has been on wide ranging grounds, and at times has adopted approaches at odds with the practice of this Court. In the event the critical issue was a narrow but important one.
3.	I shall deal with the matter under the following heads
(a)		the site and the adjoining school
(b)            the proposed development
(c)		relevant objections, the officer’s report and the consideration of the application
(d)		the sunlight issue after the resolution
(e) 		the history of the proceedings
(f)		the Claimant’s grounds
(g)		the case for LBH
(h)		discussion and conclusions.
(a)	The site and the adjoining school
4.	The site is a vacant triangular parcel of land forming the apex of the junction of Birkbeck Road and Colvestone Crescent, Dalston. To its west lies a building used for retail and restaurant purposes. To its north lies Colvestone Primary School. The areas to south east and west are akin to a town centre location, with many retail or restaurant uses. To the north lie predominantly residential and community uses.
5.	Both the site and the school lie within the St Mark’s Conservation Area. The school is a Grade II Listed Building. The application site had been occupied by buildings in the past, with a two or three storey building closer to the school building than the currently proposed development. The site was described by the planning officer in his report to committee thus:
“the vacant site currently has a negative impact on the character and appearance of the Conservation Area due to its leftover and under-utilised appearance………………the scheme….represents an enhancement of an under-utilised site and will enhance the character and appearance of the conservation area.”
6.	Between the school building and the northern edge of the appeal site lies an open area which forms part of the school’s curtilage. It is bounded by walls. Although I do not accept some of the claims of the Claimant about its role (calling it an “outdoor classroom” for example) I accept that children use it from time to time during the day, including for some organised activities, including some classes. I also have no doubt that that is of benefit to the pupils.  I accept also that it is desirable if those activities can take place in sunlight, rather than in a shaded playground, and perhaps especially so in winter months. In accepting that argument I make it plain that I consider that some of the Claimant’s asserted fears about adverse medical effects of the loss of direct sunlight were exaggerated.
7.	Plainly, as the school lies north of the application site, the effect of the proposal on daylight within that playground was a matter which would have to be considered. It is that issue which, as will become apparent, is the one of critical importance.
(b)	The proposed development
8.	The uses proposed are described above, as is the general nature of the development. The architectural style and detailing proposed in the application were welcomed by the planning officer in the report. 
9.	As noted already, the question of overshadowing was an important issue. The Applicant for planning permission had commissioned a “Sunlight and Shadow Assessment” which had been submitted to LBH before it determined the application. It was prepared by a firm called Twenty16 Design, which stated that the assessment had been commissioned to consider the impacts on the change in sunlight at the neighbouring school, and any increase in overshadowing. It was described as being based on the methodology of the BRE (Building Research Establishment) guidance, taken from “Site Layout Planning for Daylight and Sunlight” which the assessment report described as “the authoritative work in the field on sunlight and overshadowing.”
10.	It calculated sunlight hours for the 21st day of each month of the year at 10.45 am, 12.45 pm and 14.45 pm. Patently, months between the vernal and autumnal equinox will see less overshadowing as they reach midsummer day, because of the angle of the sun in the sky, and then after increasing back to the equinoctial level, the overshadowing will increase as the sun’s angle in the sky above the horizon reduces until December 21st, before increasing again to the next vernal equinox. The assessment showed that external spaces should receive 2 hours of direct sunlight on 21st March over at least 50% of the area in question (the precise assessment is set out below). It regarded that as amounting to a modest increase in overshadowing. That assessment also assumed the existence of the fourth storey, albeit a glass one.  It concluded that “the scheme can be considered acceptable in planning terms.”
11.	The reference to the percentage receiving direct sunlight is a reference to Section 3 of the BRE Publication, which deals with parks and gardens, which includes a list of amenity areas likely to be covered, including “children’s playgrounds.” It recommends as a check that at least half of the amenity area listed should receive at least two hours of sunlight on 21st March. (see BRE document [3.3.1] [3.3.3] [3.3.7] and [3.3.17].)
12.	As subsequently transpired, that report had made an erroneous assumption that the boundaries of the playground area to east and west were fenced, and in such a way that they admitted light. I shall say more on this point in due course.
(c)	Relevant objections, the officer’s report and the consideration of the application
13.	There were a number of objections, including those relating to the loss of daylight to the school and the degree of overshadowing. At the Committee Meeting concerns were expressed by a number of people (including the Claimant and the school’s headmistress) that the development would block out the sunlight from the school’s external area. Doubts were expressed about the accuracy of the assessment.
14.	An independent daylight/sunlight assessment was sought by objectors. It was also pointed out that there had been a previous refusal of listed building consent for a 2 storey development on the application site in 2005 because it would adversely affect the setting of the Listed School building, and adversely affect the appearance of the area. It is claimed by the Claimant that, after this matter had been pointed out to the Committee, it was advised that it was not relevant. That is denied in the evidence for LBH. As I shall set out below, I do not regard the Claimant’s case as giving rise to a ground for quashing the permission.
15.	The Report, and the officer’s responses at Committee, described the scheme as contributing to the vitality and viability of Dalston centre, while providing apparently desirable natural surveillance to Ridley Road by day and evening, as advocated in the Dalston Area Action Plan. It considered that the design and massing were visually interesting, consistent with the history of the site and the area, respected the scale of the adjoining school, and would enhance the character and appearance of the Conservation Area. The development was thought to be of high quality, and complied with the pertinent policies in the relevant Development Plans (Hackney Local Development Framework Core Strategy, Development management Local Plan and the London Plan. 
16.	In the responses to the objections at Committee, the officer when dealing with the objections relating to daylight and sunlight relied on the Twenty16 Design report, which he referred to as relating to the larger 4 storey development. He cited the report saying that there was compliance with the BRE Digest recommendations. He also cited the assessment’s conclusions that 87.6% of the playground currently received sunlight, which would only fall to 76.6 % which “comfortably met” BRE guidance. 
17.	The resolution to approve was passed on the casting vote of the Chair.
(d)	The sunlight issue after the resolution
18.	A subsequent report from a Consultant (Anstey Horne) was obtained by the objector in December 2015. While it was critical of some aspects of the Twenty16 assessment, it did not criticise its view that the area of amenity space it described would receive at least 2 hours of sun on March 21st.  However, after this claim had been made, and permission granted to apply for judicial review, a report came to light commissioned by the Hackney Learning Trust from a firm called Daylight Planning Limited. That report was dated 1st April 2016 and was sent to the Defendant LBH by the Claimant on 6th April 2016.  Its report suggested that there were flaws in the Twenty16 modelling. The fundamental flaw it identified was that the perimeter solid walls to west and east of the playground area had been modelled as being fenced by a barrier which admitted light through gaps, so that the amount of light entering the site from the west (and southwest) had been exaggerated.
19.	In its final form, the Daylight Planning Ltd assessment showed that whereas the playground as existing received at least 2 hours of sunlight over 82% of its area on 21st March, that figure would fall with the scheme to 57% (a fall of 25% percentage points, or by just over 30%, whereas the change previously assessed had been (88% to 77%) about 11 percentage points, or by just over 12%. The excess over the 50% benchmark would fall from 27 percentage points to 7, or from a 54% excess to one of 14%.
20.	Since then, Twenty16 has rerun its model with the walls being shown as solid. It now finds that the proper percentage is 67% (rounded). While that shows an excess, it is also right to say that Daylight Planning Ltd had looked at the amount of overshadowing during the day during the year. That work has shown that very substantial parts of the playground are in shadow for substantial parts of the school day. However, that essentially reflects the change in angle of the sun, already referred to. Given the fact that the longer school holiday of the year is that in the summer, some of the period experiencing the greater amount of sunlight than shown at the vernal equinox falls within the holiday period (i.e. from mid July to the beginning of September). 
21.	Anyone reading this judgement will be concerned to know how it was that evidence of a subsequent report was admitted into the proceedings. The general rule is of course that, as the issue for the court is whether the planning authority acted lawfully in taking the decisions it did, one is confined to material in existence at that time. That leads to the next topic.
(e)	The history of the proceedings
22.	Permission was refused on 23rd December 2015 by Collins J, but on 28th January 2016 it was granted after an oral hearing by Cranston J. The matter was listed before me on 27th April 2016. The Claimant made application by notice of 12th April 2016 to amend her grounds on the basis that LBH had proceeded on an erroneous factual basis. This was put on the basis that it fell within the original Ground 1.
23.	LBH responded by filing a witness statement from Mr Oliver Westover, the architectural technician, daylight consultant and director of Twenty16 Design (now called T16 Design). In it he responded to the Daylight Planning Ltd report. The Claimant then filed a witness statement from Chris Beck of Daylight Planning Ltd, which criticised both the original Twenty16 report, and the new response from Mr Westover.  It will thus be noted that it was not the approach of LBH to object to the admission of the evidence, but to seek to counter it.
24.	At the hearing, and from the papers, it had become quite apparent that the solicitor for the Claimant (and who was in any event a witness) was adopting an approach to a judicial review application which would not have been out of place in the County Court before the days of the current approach to litigation. In particular, he seemed to think it appropriate to draw questions for response by Mr Westover.  I was provided with emails sent out by him to both Mr Beck and Mr Westover. Indeed on 25th April 2016 he wrote to Mr Westover with a series of questions about his modelling. 
25.	However, when I raised the question of the admissibility of Mr Beck’s evidence, and of the new way of putting Ground 1, LBH did not seek to oppose it.  Being concerned to avoid unnecessary duplication, I adjourned the hearing to permit the Claimant to file evidence, limited to expert evidence by one witness, on the issue of overshadowing. The Defendant LBH was permitted to do likewise. The Claimant was to pay the Defendant the costs thrown away, to be assessed if not agreed. I also reminded the parties in open court of the differences between county court litigation and applications for Judicial Review. I sought to impress upon the Claimant’s solicitor that he was not to get involved in discussions between witnesses. As will become apparent, that very clear instruction by the Court was rapidly disregarded.
26.	In any event, Mr Beck served a second witness statement for the Claimant on 15th May 2016, which included a report. On 25th May 2016 Mr Westover served a second witness statement and report. The limit placed by my Order on the number of witness statements had been reached. Despite that, on 15th June 2016 the Claimant sought permission to file a third witness statement from Mr Beck. The evidence revealed that while the two experts had been meeting, the Claimant’s solicitor had, despite the clear instructions of the Court, been directing questions at Mr Westover. On 7th June 2016 he had sent 11 detailed questions in addition to those he had already sent on 25th April. Even if this had been a case to which CPR 35 applied, he was now asking written questions on a second occasion without the Court having given consent. 
27.	At the hearing of this matter on 23rd June 2015 I expressed my concern at this approach. I shall have something to say about this in due course on the issue of costs.
28.	In the event, the conduct of the Claimant’s solicitor did not prevent my being able to conduct the hearing. I should record also that since I sent out this judgement in draft, I have received a very full and appropriate apology from the Claimant’s solicitor. I am grateful to him for it.
(f)	The Claimant’s grounds
29.	The Claimant argued the following. I deal with her case as it was put after the exchange of evidence following my directions.
30.	Mr Jacobs’ first ground for the Claimant was that there was an error of fact. That was the assumption made that the school’s open area was bounded by fences rather than walls. The officer’s report, having cited the BRE Guidance that there should be at least two hours’ sunlight on at least half the space in question on 21st March (Report [6.3.5]) described the original assessment, and stated that the change would be from 87.6% receiving at least 2 hours of sunlight to at least 76.6% doing so, which he described as “comfortably meet(ing)” BRE guidance. He went on to refer to the fact that that was based on the original 4 storey development, and that with 3 storeys only that figure of 76.6% would be exceeded (Report [6.3.8]) which led him to conclude that there would be compliance with the relevant Development Plan policies. 
31.	The error about the wall being shown as a fence had been put before the Council by an objector (the nursery class teacher at the school). An addendum report by the officer continued to rely on the assessment as showing that the BRE requirement was met (Addendum Report [3.2] and [3.3]. )
32.	Mr Beck produced transient imaging showing the effect of the proximity of the new building on the school’s open area on June 21st and December 21st. They showed a smaller reduction in the sunlit area in June, but that in December none of the area would be sunlit.
33.	Mr Jacobs contended that this was a case falling within the category of a mistake of fact constituting a ground for judicial review, as described by Carnwath LJ in E v Home Secretary [2004] EWCA Civ 49 [2004] QB 1044 at [66].  He gave 9 reasons why he said that a different decision might have been made in the absence of the error. Some were merely different ways of saying the same thing. Their central points were:
i)	it was a split vote with a casting vote from the Chair;
ii)	if the members had concerns on this issue, they would have been reassured by the Planning Officer ;
iii)	the exceedance over 50% had changed from being “comfortable” to what Mr Jacobs called marginal;
iv)	the test of “ at least half….” was to be flexibly interpreted, as set out in BRE guidance at [1.6];
v)	the use of the outdoor area by children was one where natural light was of special importance, where BRE [1.6] said that more sunlight may be deemed necessary;
vi)	this was not a playground but an “outdoor classroom.” It was a “critical area” in terms of BRE Guidance at [3.3.12];
vii)	the reduction will exceed 20% , and therefore be in breach of BRE Guidance [3.3.11] and not the 11% figure relied on by Twenty16; (NB this submission when first made confused percentage points with percentages. It  was then corrected by Mr Jacobs. The reduction from 88% to 67% is a reduction of 24% in round terms). 
34.	His second ground was that the Committee should have adjourned to obtain a further report from an “independent” source, or alternatively should have contacted the Hackney Learning Trust for its views. 
35.	His third ground was that the officer’s report had wrongly treated the area in question as a playground rather than a learning area, and that the members had not been advised that the BRE contained any advice other that relating to the 50% benchmark. It was wrong to apply a numeric benchmark when to do so would discriminate indirectly against younger children.
36.	The officer’s advice was misleading. Reliance was placed on Oxton Farms v Selby DC [1997] EG 60, and Costas Georgiou v LB Enfield [2004] EWHC 779 per Richards J at [94].
37.	His fourth ground contended that there were breaches of the London Plan and of the National Planning Policy Framework (NPPF) because the effect of the proposal on the outdoor facility was not properly addressed. It argued that there was a breach of policies resisting losses in educational provision. 
38.	His fifth ground argued that the previous refusal of planning permission required the Committee to consider whether its decision would be consistent (on the principle in the line of cases culminating in Fox Strategic Land and Property Ltd. v Secretary of State for Communities and Local Government [2013] 1 P. & C.R. 6, at paragraphs 12 to 14, citing the judgment of Mann L.J. in North Wiltshire District Council v Secretary of State for the Environment [1992] 65 P. & C.R. 137, at p.145) Here, the Council was informed of the decision by an objector, but advised that it was not relevant. However the evidence was that the Committee invited the Applicant to address the Committee about it.
39.	His sixth ground was that there had been a breach of ss 66 and 72 of the Planning (Listed Building and Conservation Areas) Act 1990, and a failure to apply NPPF paragraphs 133-134 by failing to consider the visual effect of the development on the school. Reference was also made to Barnwell Manor Wind Energy Ltd v E Northants DC [2014] EWCA Civ 137 [2015] 1 WLR 45 at [129].
(g)	The case for LBH
40.	Mr Atkinson concentrated on the principal issue above, namely the effect of the error being made about the wall, and its consequent effects on the daylight assessment. He did so at my invitation, because as will become apparent, my judgement is that the other grounds are unarguable, or are simply a duplication of that main ground. 
41.	Mr Atkinson accepted that there had been an error about the nature of the wall. It was, he said, relevant as one input. But the argument was about what the effects would be, which was a matter of opinion, not a question of fact. However the error, if that is what it was, was pointed out to the Committee by objectors. 
42.	The effect of the continuing dispute is such that there is no established or uncontentious fact, which is required for the test in E v Home Secretary  to apply.
43.	 In any event, even with the corrections, all the figures are above the 50% guideline. One may be confident that if the true position had been known, the decision would have been the same. 
(h) 	Discussion and conclusions
44.	This development was considered in a very thorough report by the planning officer. I have not gone through it all, but it sets out the arguments for and against the development properly and fairly. Some of the Claimant’s attacks are misdirected or rest upon matters of semantics, such as the argument whether it was an “outdoor classroom” or a “playground”. The label does not matter: but its value to and use by the staff and children does. No one seriously imagines that education only occurs within a school building, or that playgrounds only have a recreational function, and nothing in the LBH case, or in its officer’s report, or in the Applicant’s documentation justify the criticism on this point. However, the area in question would still be usable for its current purpose. The difference will be that in the winter months it would be in more shade, and in some part of that period entirely in shade. But that is also the period when it will in any event be a less attractive space to use given the climatic conditions. I accept however that the changes in its exposure to sunlight would have some adverse effect on the function of the external area.
45.	One can also safely put to one side the arguments that there was a breach of s 66 or 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 or a failure to consider or apply paragraphs 133-4 of the NPPF. The duty to consider the preservation or enhancement of the listed building and the Conservation Area was properly addressed. One may also pass over the Claimant’s allegations that this amounted to a loss of educational provision. It patently did not. 
46.	As to the alleged failure to address the earlier refusal, I accept that it was originally overlooked. But it was dealt with before the Committee. In any event, the furthest it could take anyone would be to say that attention should be paid to massing and the relationship of the two buildings. That was done, and at considerable length. These were different proposals, albeit on the same site. It is impossible to argue that it would have had any material effect on that subsequent discussion. 
47.	There can be no possible complaint that there was no adjournment to consult another body. If an objector had wanted to get that body’s views before the Committee that was a matter for the objector.
48.	I turn now to the principal ground. I start by referring to the judgement of Carnwath LJ in E v Home Secretary at [58]- [67]. I have cited the whole passage because it identifies the rationale of the principles identified by Carnwath LJ (as he then was) at [66].
“Mistake of law in practice
58	Timothy Jones cites a number of cases, particularly in the context of town and country planning, where decisions have been set aside because of errors of fact (albeit without detailed discussion of the principle). Examples are: 
(i) An inspector's mistaken understanding that land had never been part of the Green Belt: Hollis v Secretary of State (1984) 47 P&CR 351 (Glidewell J).
(ii) An inspector's mistaken view that a building extension would not obstruct a particular aspect: Jagendorf v Secretary of State [1985] JPL 771 (David Widdicombe QC).
(iii) The minister's misinterpretation of the inspector's conclusions on evidence relating to viability of restoration of a building: Barnet Meeting Room Trust v Secretary of State 13.12.89 unreported (Sir Graham Eyre QC).
59	More significant, because it was a fully reasoned decision of the Court of Appeal, was another planning case, Simplex GE (Holdings) Ltd v Secretary of State for the Environment (1989) 57 P&CR 306. The Secretary of State in rejecting the planning appeal had mistakenly thought that the council had carried out a study relevant to the inclusion of the site in the Green Belt, whereas the study related only to what uses should be made within the Green Belt designation. The decision was challenged on the basis that "as a result of the error of fact" the Minister had "taken into account matters which he was not entitled to consider" (p 322). The Court of Appeal accepted that formulation, holding that the error was "undeniably significant in the decision-making process" (p 327, per Purchas LJ), or was one which "was or may have been material" (p 329, per Staughton LJ). The decision was therefore quashed. 
60	As will be seen, the cases of Haile (mistake as to the name of a political party) and Khan (ignorance of a conviction in Bangladesh) are best explained as further examples in this Court of the same approach to plain errors of fact, as applied in the field of asylum law. 
Underlying principle 
61	As the passage cited by Lord Slynn shows, the editors of the current edition of De Smith (unlike Wade and Forsyth) are somewhat tentative as to whether this is a separate ground of review: 
"The taking into account of a mistaken fact can just as easily be absorbed into a traditional legal ground of review by referring to the taking into account of an irrelevant consideration or the failure to provide reasons that are adequate or intelligible or the failure to base the decision upon any evidence." (para 5/-094).
62	 We are doubtful, however, whether those traditional grounds provide an   adequate explanation of the cases. We take them in turn: 
(i) Failure to take account of a material consideration is only a ground for setting aside a decision, if the statute expressly or impliedly requires it to be taken into account (Re Findlay [1985] AC 318, 333-4, per Lord Scarman). That may be an accurate way of characterising some mistakes; for example, a mistake about the development plan allocation, where there is a specific statutory requirement to take the development plan into account (as in Hollis). But it is difficult to give such status to other mistakes which cause unfairness; for example whether a building can be seen (Jagendorff), or whether the authority has carried out a particular form of study (Simplex). 
(ii) Reasons are no less "adequate and intelligible", because they reveal that the decision-maker fell into error; indeed that is one of the purposes of requiring reasons. 
(iii)  Finally, it may impossible, or at least artificial, to say that there was a failure to base the decision on "any evidence", or even that it had "no justifiable basis" (in the words of Lord Nolan: see above). In most of these cases there is some evidential basis for the decision, even if part of the reasoning is flawed by mistake or misunderstanding. 
63      In our view, the CICB case points the way to a separate ground of review, based on the principle of fairness. It is true that Lord Slynn distinguished between "ignorance of fact" and "unfairness" as grounds of review. However, we doubt if there is a real distinction. The decision turned, not on issues of fault or lack of fault on either side; it was sufficient that "objectively" there was unfairness. On analysis, the "unfairness" arose from the combination of five factors: 
i)	An erroneous impression created by a mistake as to, or ignorance of, a relevant fact (the availability of reliable evidence to support her case); 
ii)	The fact was "established", in the sense that, if attention had been drawn to the point, the correct position could have been shown by objective and uncontentious evidence; 
iii)	The claimant could not fairly be held responsible for the error;
iv)	Although there was no duty on the Board itself, or the police, to do the claimant's work of proving her case, all the participants had a shared interest in co-operating to achieve the correct result
v)	The mistaken impression played a material part in the reasoning.
64	If that is the correct analysis, then it provides a convincing explanation of the cases where decisions have been set aside on grounds of mistake of fact. Although planning inquiries are also adversarial, the planning authority has a public interest, shared with the Secretary of State through his inspector, in ensuring that development control is carried out on the correct factual basis. Similarly, in Tameside, the Council and the Secretary of State, notwithstanding their policy differences, had a shared interest in decisions being made on correct information as to practicalities. The same thinking can be applied to asylum cases. Although the Secretary of State has no general duty to assist the appellant by providing information about conditions in other countries (see Abdi and Gawe v Secretary of State [1996] 1 WLR 298, he has a shared interest with the appellant and the Tribunal in ensuring that decisions are reached on the best information. It is in the interest of all parties that decisions should be made on the best available information (see the comments of Sedley LJ in Batayav, quoted above). ………………………..
65	The apparent unfairness in CICB was accentuated because the police had in their possession the relevant information and failed to produce it. But, as we read the speeches, "fault" on their part was not essential to the reasoning of the House. What mattered was that, because of their failure, and through no fault of her own, the claimant had not had "a fair crack of the whip". (See Fairmount Investments v Secretary of State [1976] 1 WLR 1255, 1266A, per Lord Russell.) If it is said that this is taking "fairness" beyond its traditional role as an aspect of procedural irregularity, it is no further than its use in cases such as HTV Ltd v Price Commission [1976] ICR 170, approved by the House of Lords in R v IRC ex p Preston [1985] AC 835, 865-6.) 
66	In our view, the time has now come to accept that a mistake of fact giving rise to unfairness is a separate head of challenge in an appeal on a point of law, at least in those statutory contexts where the parties share an interest in co-operating to achieve the correct result. Asylum law is undoubtedly such an area. Without seeking to lay down a precise code, the ordinary requirements for a finding of unfairness are apparent from the above analysis of CICB. First, there must have been a mistake as to an existing fact, including a mistake as to the availability of evidence on a particular matter. Secondly, the fact or evidence must have been "established", in the sense that it was uncontentious and objectively verifiable. Thirdly, the appellant (or his advisers) must not been have been responsible for the mistake. Fourthly, the mistake must have played a material (not necessarily decisive) part in the Tribunal's reasoning. 
67	 Accordingly, we would accept the submissions of each of the present appellants, that, if the new evidence is admitted, the Court will be entitled to consider whether it gives rise to an error of law in the sense outlined above. As we have said, however, whether the evidence should be admitted raises a separate question to which we now turn.”

49.	I therefore take the four criteria at [66] and seek to apply them to the facts in this case. Firstly, was there a mistake as to an existing fact, including a mistake as to the availability of evidence on a particular matter? It is clear that the Committee, advised by its officer in good faith, treated the situation on the ground as it was assumed to be by the Twenty16 assessment taking it as its base. It is correct that at least one objector pointed out the fact that the model showed that the walls were solid and did not admit light, but the Committee was advised by the officer that the assessment showed that the guidelines were “comfortably” met. In my judgment, one has to approach this in the context of fairness, as per Carnwath LJ at [65]- [66] in E v Home Secretary. Here, the Twenty16 assessment was treated as being authoritative by the officer in his advice to the Committee. In my judgment a misleading picture (albeit without any intention to mislead) had been created, to the disadvantage of the objectors (including the Claimant) on a critical issue.
50.	Secondly, was the fact or evidence "established", in the sense that it was uncontentious and objectively verifiable? While there is still some disagreement on the effect of the error (i.e. there is a difference between the assessment of the effect of the overshadowing in terms of the excess over the 50% benchmark), there is no dispute that there was an error, nor that it related to how one modelled the flank walls of the playground. I therefore consider that this criterion is met. 
51.	Thirdly, is it the case that the Claimant (or her advisers) were responsible for the mistake? The answer is that they were not.
52.	 Fourthly, did the mistake play a material (not necessarily decisive) part in the Tribunal's reasoning? In my judgment one must apply this criterion by asking if it is possible to say that it did not (in other words the test in Simplex GE (Holdings) Ltd v Secretary of State for the Environment (1989) 57 P&CR 306, albeit not in the passage cited by Carnwath LJ at [59] in E v Home Secretary). It is also the effect of the new statutory test in section 31(2A) of the Senior Courts Act 1981 as amended by Criminal Justice and Courts Act 2015. I consider that this error, and the assessment which flowed from it, did play a material part in the decision making process. While it is true that the assessment still shows an excess over the 50% benchmark, the assessments on both sides of the argument show a significant reduction in daylight, and the description of being “comfortably met” is not one which can necessarily be read across from the first assessment by Twenty16 to its successor.   I appreciate that LBH was not required to give reasons for its decision, but there can be no doubt that this matter assumed importance at the meeting, nor the firm terms in which the officer advised the Committee.  
53.	I therefore consider that this ground of challenge is made out. None of the other grounds have any discernible merit in law.
54.	However in reaching the conclusion that the permission must be quashed, I must make one matter crystal clear. The planning merits of the application are not a matter for this court. My judgement is not to be taken as implying that the Committee, had it known the full picture on the daylight assessment, either would have refused permission, or that it should have done so. This Court is wholly neutral on whether LBH should grant or refuse the application when it reconsiders it.  There was a strong case made for the grant of permission, and it will be for LBH to determine whether the case for the development or against it should succeed. 
55.	In my draft judgement, I had invited submissions as to permission to appeal, costs or on any other relevant matter. Both Claimant and Defendant made written submissions on the issue of costs, for which I am grateful.
The Costs issues
56.	The Claimant contends that she should receive all of her costs, following the general rule in CPR 44.3 (2), save that the costs awarded against the Claimant on 27th April 2016 should be paid or set off.  The Claimant further argues that while she did not succeed on all grounds, it would be wrong to adopt an “issue based approach,” because she succeeded on the principal issue in the case, namely overshadowing. The other matters were subsidiary points on which little time was spent at the hearing. 
57.	I shall set out the Claimant’s answers to the Defendant’s submissions after setting out the latter.
58.	The Defendant makes three submissions:
i)	the Claimant must be ordered to pay the sum of £ 3142 (the agreed sum of the costs thrown away as referred to in the order of 27th April 2016) in any event. The costs thrown away should be added to the Aarhus capped sum which the Defendant is ordered to pay. That is because the case for the Claimant was recast at the hearing of 27th April as case of a mistake of fact;
ii)	the Claimant should be ordered to pay the Defendant’s costs, assessed on an indemnity basis, because of the conduct of the Claimant’s solicitor as set out in the judgement. Further the Claimant’s legal team has approached this case throughout as thought the Court’s task was to address the planning merits, rather than address the lawfulness of the decision and the manner in which it was reached;
iii)	only one sixth of the Claimant’s claimed costs should be paid by the Defendant, as five of the six grounds were dismissed. The issue based approach is appropriate in accordance with CPR 44.2(4)(b). While they did not take up much time at the hearing, they consumed a great deal of work in case preparation. On 27th April 2016 the Court warned the Claimant and her legal team that her case needed more focus, and that parts of the claim were rather optimistic, but the same points as had drawn that comment continued to be argued thereafter. In the event, the Court held the other grounds to be of no discernible merit.
59.	The Defendant enlarges the third point as follows:
i)	each of the Claimant’s six grounds of challenge were detailed and raised discrete issues that required careful consideration and a full response from the Defendant;
ii)	the success of each of the Claimant’s grounds did not rely upon the success of any other ground;
iii)	none of the six grounds was explicitly identified in advance as being of more importance than the others;
iv)	indeed the successful ground emerged only with the application to amend the grounds made on 12th April 2016;
v)	the Defendant contested this claim in the public interest, applying scarce public resources to defending its decision-making.
vi)	six points were raised, five were without merit.  Accordingly the Defendant should be ordered to pay no more than 17% of the Claimant’s reasonable costs, in accordance with CPR 44.2(6).
vii)	in the alternative, should the Court disagree that 17% represents the correct percentage of the Claimant’s costs to be awarded, this figure should not exceed 30%.
60.	The Claimant contends that her solicitor believed, rightly or wrongly, that it was appropriate to question the witness pursuant to CPR 35.9, 35.6 and 54.23. His conduct was designed to achieve expedition. Eventually on 12th June 2016 the Defendant LBH, having originally objected to the solicitor putting further questions on 7th June 2016, agreed to the Claimant’s request that he could do so, provide they were proportionate and were only for the purpose of clarification. The Application to adduce further evidence from the Claimant’s expert in response to the Defendant’s was made on 15th June 2016. The Defendant withdrew its objection on 21st June 2016. In the premises, no prejudice was caused, and the answers given by Mr Westover formed part of his report.
Conclusions on Costs
61.	I approach this issue bearing in mind the matters set out in CPR 44.2, and in particular 44.2(2) (4),(5) and (6).
62.	This claim could only have succeeded on the basis of the argument as it was eventually coined- i.e. the mistake of fact which I have found underlay the approach of the Defendant Council and its planning officer. For the reasons I have given in the judgement, the other claims were of no discernible merit. It follows that until the Claimant advanced that argument, she would have failed in her claim.  However once that claim was made, and in particular once the flaw had been identified about the modelling of the nature of the western and eastern boundaries of the playground area, the claim was on a firm footing. 
63.	That can be tested. For basic reasons of public law, is not for the Court to say that it would have agreed or disagreed with the expert opinion presented to the Committee. The claim as originally argued was in reality an attempt to persuade the Court that the opinion of the original assessor of overshadowing, and of the planning officers, was wrong, simply because another expert disagreed. That could not have justified the quashing of the permission. None of the other grounds could have done so either. 
64.	It follows in my judgment that the Claimant should not be entitled to any costs against the Defendant until 27th April 2016. Further, the Defendant is entitled to an order of costs against the Claimant for its defence of the action until that date (giving credit for the sum of £ 3142.)
65.	After that date the picture is different. From then on, it appears to me that virtually all the conduct of the action related to the one successful ground, and the Claimant should be entitled to her reasonable costs of pursuing the action thereafter. While I have no doubt that the Claimant’s solicitor should have listened more attentively to the Court’s advice that the matter was not one where an “ordinary” litigation approach was appropriate, I do not consider that his approach, unwise though it was, added to the costs of the action significantly. I agree with the Defendant’s submission that the Claimant persisted in arguing unfocused and optimistic grounds, but I am not persuaded that that added to the time of hearing. The one exception I make is that the Claimant should be disallowed the costs of the making and filing of Mr Beck’s final witness statement. I also draw to the attention of the costs judge that the second day of the hearing was not a new hearing date, but the second day of the hearing. The costs judge will no doubt reflect on the fact that those parts of the skeleton relating to the other grounds for the second part of the hearing were simply carried forward from the old.
66.	I do not consider that this is a case for awarding costs on an indemnity basis. I also consider that the Aarhus protective costs cap must continue to apply. There is of course a costs cap of £ 35,000 in respective of the costs the Claimant may receive from the Defendant, but it is inconceivable that the costs order I make will produce a claim , let alone an assessed bill, that comes anywhere near that figure. 
67.	I shall not make a summary assessment, as the effect of my order requires that the claims for costs be disentangled. The one exception to that is the amount of costs payable to the Defendant will be capped at £ 6000, because it is an Aarhus claim. I am confident that those costs will comfortably exceed £6000, which is the amount I therefore award. My Order as to costs is as follows: 
i)	the Claimant is to pay the Defendant’s costs of defending the action until 27th April 2016, summarily assessed in the sum of £ 6000.
ii)	the order of costs of 27th April 2016 in favour of the Defendant is set aside.
iii)	the Defendant must pay the costs of the Claimant of the action, limited to those costs incurred after 27th April 2016, but not including the costs of Mr Beck’s final witness statement, and further limited to such costs as were reasonably incurred in advancing the successful ground of challenge. Such costs are to be assessed in default of agreement.