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	England and Wales High Court (Administrative Court) Decisions
You are here: BAILII >> Databases >> England and Wales High Court (Administrative Court) Decisions >> Kent, R (on the application of) v Royal Borough of Kensington & Chelsea & Ors [2016] EWHC 2809 (Admin) (08 November 2016) URL: http://www.bailii.org/ew/cases/EWHC/Admin/2016/2809.html Cite as: [2016] EWHC 2809 (Admin)

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IN THE HIGH COURT OF JUSTICE
QUEEN'S BENCH DIVISION
PLANNING COURT

		Royal Courts of Justice Strand, London, WC2A 2LL
		08/11/16

Mr Justice Hickinbottom :

Introduction

1. In these proceedings, the Claimant challenges the decision of the Defendant local planning authority ("the Council") dated 27 January 2016 to grant planning permission to the Interested Parties for development including the excavation of a single storey basement and the removal and reconstruction of a rear closet wing, at 26 Portland Road, London W11 ("the Property"). The Property is mid-terrace in a row of four houses. The Claimant jointly owns the adjacent property, the other mid-terrace house, at 24 Portland Road.
2. The Property, which was built in about 1850, lies within the Norland Conservation Area, and backs onto the Ladbroke Conservation Area. It has four storeys and, like many Victorian town properties, it has access from the street by way of two sets of steps, one leading up to a floor which the Interested Parties refer to as "the upper ground floor"; and one leading down to a floor referred to as "the lower ground floor". I shall use those same terms to describe those two storeys. To the rear of the Property, there was originally a conventional two-storey "closet wing" across about half the width of the property. At the rear, there was also a small courtyard, beyond which was a raised garden. The courtyard was at the same level as the floor level of the lower ground floor.
3. In the 1960s, the lower ground floor appears to have been sublet as a flat. In 1965, the tenant of what was described as "the ground floor flat" applied for planning permission to erect a 10-foot-long extension for use as a kitchen. It is unclear if that permission was granted, but it seems unlikely that it was ever implemented; because, in 1967, there was another application for planning permission to demolish the closet wing and replace it with a four-storey wing with a slightly larger (i.e. wider) footprint, which was granted and implemented. In that application, the lower ground floor is referred to as "the basement". At some point, the owners of No 24 also replaced their existing closet wing – immediately adjacent to that at the Property – with a four-storey wing of the same height.
4. In the 1990s, the courtyard at the rear of the Property was enclosed through the erection of a conservatory, which required the removal of some of the garden earth so that there was a suitable garden slope. It seems that that was built pursuant to permitted development rights.
5. On 27 November 2015, the Interested Parties applied for planning permission for various works to the Property, including a single storey basement, excavated below the footprint of the house and extending beneath part of the rear garden. There were three objections to the proposal, one being from the Claimant, as next door neighbour. He objected to the proposal on the basis that it would breach the Council's own policy in respect of basement development, namely Policy CL7 of the Council's Consolidated Local Plan. In representations which chime with the primary ground in this claim, he said:

"No 26 has previously been the subject of substantial extension at existing basement level on two occasions…. These historic basement extensions comprise 'basement' development under the [Council's] basement policy definitions because they were built below the prevailing ground level of No 26 at the street front and garden rear."

6. However, that objection was rejected; and, on 27 January 2016, planning permission for the proposed development was granted by the Council's Executive Director (Planning and Borough Development), under delegated powers, on the basis of an Officer's Report ("the Officer's Report") prepared by one of the Council's Planning Officers, Ms Cheryl Saverus ("the Planning Officer"). It is, of course, that decision which the Claimant now challenges.
7. Before me, Miss Megan Thomas appeared for the Claimant, and Miss Isabella Tafur for the Council. At the outset, I thank them for their contribution.

The Relevant Policy

8. In terms of planning, West London is closely developed with some of the highest density housing in the country. The pressure on the availability of land, and the planning challenges for upward development, has resulted in a dramatic increase in the numbers of applications for basements and basement extensions received by the Council. In 2003, it received 64 applications; in 2008, 212; and, in 2013, 450.
9. The advantages of such development are clear: once completed the development is largely hidden from view. However, there are also potential planning disbenefits. The construction of a basement may disrupt the topography of the garden. Excavation inevitably brings structural engineering challenges; although these are limited where the ground comprises London clay, and the planning process can ensure that any development is structurally safe. Importantly, excavation also has a substantial and inevitable impact on the quality of life for neighbours during the course of the works, through noise, vibration, dust and transport. The greater the excavation, the greater this impact is likely to be.
10. As the number of planning applications for development beneath existing properties rose, the Council's concerns increased. Following consultation, in 2008, the Council commissioned Ove Arup to prepare a Subterranean Development Scoping Study, which was used to inform its emerging policy approach to so-called "subterranean development"; and, in May 2009, the Subterranean Development Supplementary Planning Document ("SPD"), which was supplementary guidance to the application of the then-Local Planning Framework. The SPD, for example, indicated that basement coverage would generally be restricted to no more than 85% of the garden space. The SPD applied to all "subterranean development", defined to include "all development underground, either under existing structures or under gardens, and in particular large subterranean rooms and spaces; new basements and basement extensions" (paragraph 1.2).
11. However, over time, the Council began to doubt whether that SPD was adequate. In 2012-13, it proposed, and consulted upon, a review of its "basement policy". In March 2013, the Council published its second draft policy for public consultation, which proposed, as new Policy CL7 of the now-Consolidated Local Plan, that all "basement development" should (amongst other things) "not comprise more than one basement storey nor add a further basement floor to an existing basement", and "not exceed 50% of each garden of the property". As to scope, it was said (at paragraph 34.3.46 of the reasoned justification for the draft policy):

"The Policy applies to all basement proposals: extensions, and new developments, across all land uses. 'Basement' means one or more floor levels substantially below the prevailing level of the back gardens. Lower ground floors are not regarded as basements in this context. A basement will not be allowed where a property already has an existing basement."

12. There were a substantial number of comments from consultees who were concerned about the definition of "basement", to which the Council consistently responded (in its formal Consultation Response on Second Draft Basements Policy (July 2013)):

"It is acknowledged that the definition of basement needs more clarity and text will be altered as appropriate."

13. In respect of one particular comment (from a Michael and Jacqueline Hayes), the Council responded as follows:

"Comment

The distinction between lower ground floors and basements is not made clear. At what stage does a lower ground floor become a basement? Both usually involve the entire bottom floor being situated below ground level, so that the problems that arise when further excavation takes place are similar for both.

Accordingly, the policy should treat existing lower ground floors as basements, and prohibit excavation beneath floors which are below ground, whether or not they might be considered as basements or lower ground floors.

Council's response

It is acknowledged that the definition of basement needs more clarity and text will be altered as appropriate.

The suggestion would put a stop to most basement proposals in the Borough. The policy is not intended to stop basement development. The proposed policy would allow people to extend their homes and help minimise their impacts."

14. From these responses, it seems clear that the Council was aware that the definition of "basement" needed reconsideration; and, in particular, that the issue "lower ground floors" of the type at the Property – common in its area – needed to be addressed further. It also seemed to be averse to defining "basement" to include all lower ground floors.
15. Because the review of the basement policy comprised a partial review of the Council's Core Strategy, the proposed new Policy CL7 had to be subject to public examination under section 20(5) of the Planning and Compulsory Purchase Act 2004. As examiner, the Secretary of State appointed a planning inspector, David Vickery DipT&P MRTPI ("the Examiner"). The wording of the actual Policy CL7 subject of the examination, so far as relevant to this claim, was as follows:

"The Council will require all basement development to:

(a)  not exceed a maximum of 50 per cent of each garden or open part of the site…;

(b)  not comprise more than one storey…;

(c)  not add further basement floors where there is an extant or implemented planning permission for a basement or one built through the exercise of permitted development rights;…".

16. Paragraph 34.3.46 of the justification for the policy, in respect of scope, had changed since the earlier draft. It now said:

"This policy applies to all new basement development. For the purposes of this policy, basement development is the construction or extension of one or more storeys of accommodation below the prevailing ground level of a site or property."

17. The rationale for Policy CL7(b) and (c) policy was then set out, as follows:

"34.3.47 Basements are a useful way to add accommodation to homes and commercial buildings. While roof extensions and rear extensions add visibly to the amount of built development, basements can be built with much less long term visual impact – provided appropriate requirements are followed. This policy sets out these requirements.

34.3.48 Basement development in recent years has been the subject of concern from residents. Basements have given rise to issues about noise and disturbance during construction, the management of traffic, plant and equipment, and concerns about the structural stability of buildings. These concerns have been heightened by the growth in the number of planning applications for basements in the Royal Borough…. The vast majority of these are extensions under existing dwellings and gardens within established residential areas.

34.3.49 In the Royal Borough, the construction of new basements has an impact on the quality of life, traffic management and the living conditions of nearby residents and is a material planning consideration. This is because the borough is very densely developed and populated. It has the second highest population density and the highest household density per square km in England and Wales. Tight knit streets of terraced and semi-detached houses can have several basement developments under way at any one time. The excavation process can create noise and disturbance and the removal of spoil can involve a large number of vehicle movements.

34.3.50 A basement development next door has an immediacy which can have a serious impact on the quality of life, while the effect of multiple excavations in many streets can be the equivalent of having a permanent inappropriate use in a residential area. There are also concerns over the structural stability of adjacent property, character of rear gardens, sustainable drainage and the impact on carbon emissions. Planning deals with the use of land and it is expedient to deal with these issues proactively and address the long term harm to residents' living conditions rather than rely only on mitigation. For all these reasons the Council considers that careful control is required over the scale, form and extent of basements.

34.3.51 The policy therefore restricts the extent of basement excavation to no more than under half the garden or open part of the site and limits the depth of excavation to a single storey in most cases….

34.3.52 'Garden' or 'open part of the site' is the private open area to the front, rear or side of the property. A 'single storey' is one that cannot be subdivided in the future to create additional floors. It is generally about 3 to 4 metres floor to ceiling height but a small extra allowance for proposals with a swimming pool may be permitted.

34.3.53 Restricting the size of basements will help protect residential living conditions in the borough by limiting the extent and duration of construction and by reducing the volume of soil to be excavated. Large basement construction in residential neighbourhoods can affect the health and wellbeing of residents with issues such as noise, vibration and heavy vehicles experienced for a prolonged period. A limit on the size of basements will reduce this impact.

…

34.3.58 Where a basement has already been implemented following the grant of planning permission or through the exercise of permitted development rights, the policy does not allow further basement floors or basement extensions that would exceed 50 per cent of the garden or open part of the site. This is to ensure consistency of approach."

18. That rationale is clear: although there were other concerns, the overwhelming driver for this policy was to limit the adverse effects of the excavation and construction of basements in dwellings, by generally limiting any development to the excavation and construction of one basement storey only.
19. The Examiner reported on 2 December 2014.
20. He referred to the issue of definition of "basement", that had been raised by consultees. He said (in paragraph 29 of his Report);

"It was said that the term 'basement' was not adequately defined in the Policy at 34.3.46. However, I think that it is a common sense and short definition; that it is clear to everyone what is meant; and that it is capable of consistent interpretation. The Council told me that it has not had a problem with that definition over the last 10 years (although its current SPD's title is 'subterranean' development). Any disputes will be rare and are unlikely to be resolved by a longer or more complicated definition (which itself could create problems of interpretation). Therefore, I conclude that the definition is sound."

21. The Examiner concluded that Policy CL7(a) and (b) were both justified, effective and consistent with national policy (paragraphs 41-69). He considered, in considerable detail, the adverse effects of excavation and construction of basements on neighbours (paragraph 48 and following). In relation to Policy CL7(b) (the "one storey restriction"), he concluded that, although there was a legitimate demand for investment in houses, given the evidence that, in general, larger basements cause greater adverse impacts to neighbours, the restriction was justified.
22. With regard to Policy CL7(c), he said:

"70. Given my findings above on CL7(a) and (b), it logically follows that additional basement floors which might follow on after an extant or implemented permission or after the implementation of permitted development rights should be prevented.  Otherwise CL7(b) would not be effective or reasonable or fair.  For the same reasons, this criterion should also be subject to the recommended monitoring and review modifications in order to be sound.

71. The Council said that this would not apply where a property already had an existing basement before the need for planning permission came into effect with the 1947 Planning Act.  The Council said this would be 'fair', which I take also to mean 'reasonable' and 'proportionate', and that it would be consistent with national planning legislation in Development Orders when restrictions on development rights are introduced.  I agree. Unfortunately, the policy at 34.3.58 does not say this and so is not sound. Modification MM6 rectifies this unsoundness. I have slightly altered the Council's wording to make clear that both originally constructed and later added basements must have taken place before 1 July 1948.

72. I conclude that with the above modification CL7(c) is justified, effective and consistent with national policy."

In other words, Policy CL7(c) was needed to prevent cumulative applications for basement development being used to overcome the restriction of such development to a single storey. Without Policy CL7(c), applicants could repeatedly apply for and secure permission for single storey basement developments, one below the other, which would be contrary to the policy intention and in substantive frustration of Policy CL7(b).

23. The modification proposed by the Examiner, to what became paragraph 34.3.57, was as follows (the addition being italicised):

"Where a basement has already been implemented following the grant of planning permission or through the exercise of permitted development rights, the policy does not allow further basement floors or basement extensions that would exceed 50 per cent of the garden or open part of the site. This provision would not apply to a basement which forms part of the original property or to a later addition which were constructed prior to 1 July 1948. This is to ensure consistency of approach."

24. The Examiner was satisfied that, subject to that and other modifications irrelevant to this claim, the proposed policy was sound; and, in July 2015, the Council adopted it, with the modification to paragraph 34.3.58 as the Examiner proposed, as part of its Consolidated Local Plan.

The Grounds of Challenge

25. The Claimant relies upon two grounds of challenge, namely that, in deciding to grant planning permission:

Ground 1: The Council relied upon an erroneous construction of Policy CL7.

Ground 2: The Council failed properly to have regard to preserving or enhancing the character and appearance of the Norland and Ladbroke Conservation Areas. As discrete sub-grounds, it is said that the Council relied upon two material perverse findings of fact.

26. I will deal with those grounds in turn.

Ground 1: Policy CL7

27. The relevant law with regard to the interpretation and application of planning policy is well-settled. The principles particularly relevant to the Claimant's primary ground are as follows.

i) Section 70(2) of the Town and Country Planning Act 1990 provides that, in dealing with an application for planning permission, a decision-maker must have regard to the provisions of "the development plan", as well as "any other material consideration". "The development plan" sets out the local planning policy for an area, and is defined by section 38 of the Planning and Compulsory Purchase Act 2004 to include adopted local plans.

ii) Section 38(6) of the 2004 Act provides:

"If regard is to be had to the development plan for the purpose of any determination to be made under the planning Acts the determination must be made in accordance with the plan unless material considerations indicate otherwise."

Section 38(6) thus raises a presumption that planning decisions will be taken in accordance with the development plan, but that presumption is rebuttable by other material considerations.

iii) In order to have proper regard to a policy, the decision-maker must have interpreted it properly. The true interpretation of policy is a matter of law for the court to determine, policy statements being "interpreted objectively in accordance with the language used, read as always in its proper context" (Tesco Stores Ltd v Dundee City Council [2012] UKSC 13 ("Tesco Stores") at [19] per Lord Reed).

28. Turning to this case, there is some common ground, notably:

i) Miss Thomas and Miss Tafur agreed – in my view, rightly – that, in determining and applying the true construction of Policy CL7, the terms used from time-to-time to describe a particular storey of a building are not likely to be helpful: and so the fact that the Interested Parties refer to the lowest floor in their house as "the lower ground floor", or that some of the earlier planning application documents refer to it as "basement", does not assist.

ii) It is uncontroversial that the proposed development to the Property is "basement development" as defined in paragraph 34.3.46 of the supporting text to Policy CL7; because, on any view, it would involve the construction of a storey below prevailing ground level. Policy CL7 therefore applies.

iii) It is also common ground that the 1967 and 1990s works extended the lower ground floor, with planning permission or under permitted development rights.

iv) Furthermore, it is clear that the construction of a basement at the Property, in line with the proposal, will cause "material harm to the living conditions of neighbouring properties": so much is noted in paragraph 6.24 of the Officer's Report.

29. However, there, Miss Thomas and Miss Tafur go their separate ways. In particular, they are at odds as to how Policy CL7(c) should be construed and applied to this case.
30. Under Policy CL7(c), further basement floors cannot be added to a property where "there is an extant or implemented planning permission for a basement or one built though the exercise of permitted planning rights". As her main contention under this ground, Miss Thomas submitted that, where a proposal is for basement development, the application of the policy thus requires the decision-maker to determine whether the property already has "basement development" as defined in paragraph 34.3.46 read with paragraph 34.3.57, i.e. whether it has a storey of accommodation below the prevailing ground level of the site or property, which storey has been constructed or extended since 1 July 1948. This requires an intermediate determination of where the "prevailing ground level of the site or property" is; and then subsequent consideration of whether the relevant extant storey of accommodation is, or is not, below it.
31. Miss Thomas readily accepted that each of those questions is fact-specific, and each involves the exercise of planning judgment so that, in any particular circumstances, there is a range of legitimate responses. Indeed, she conceded in debate that, in relation to the Property, it would have been open to the Planning Officer to have considered the prevailing ground level, and found it to have been the floor level of the lower ground floor; so that the lower ground floor as a storey would not been below that level and therefore not a "basement" for the purposes of Policy CL7. However, there is nothing in her Officer's Report that suggests the Planning Officer ever brought her mind to bear on this issue. The Officer, whose analysis the decision-maker adopted, fell into legal error by never addressing the crucial questions required by Policy CL7. As a result, she proceeded on the basis that the proposal complies with Policy CL7, whereas it does (or might) not.
32. Furthermore, Miss Thomas submitted, when the Planning Officer was asked to do so after the event, she still did not address the right issues. For example, in her email of 2 February 2016 to the Claimant, she suggested that the lowest floor of a dwelling (whatever that might be called) could never be a "basement", irrespective of where the prevailing ground level might be. Further, the Council's response of 4 March 2016 to the Claimant's letter before action, presumably written on instructions informed by the Planning Officer's view, suggests that "below the prevailing ground level" means "wholly below" that level, and the lower ground floor is therefore not a "basement" simply because it is, albeit largely, only partially below the prevailing ground level. Miss Thomas submitted that, in all the circumstances, I should not be satisfied that the failure of the Planning Officer to adopt the correct construction of the policy was immaterial; nor should I be satisfied that, had she considered the questions as she ought, it is highly likely that the Planning Officer would have granted planning permission in any event. The decision to grant planning permission, based upon the Planning Officer's flawed approach, should therefore be quashed; and the matter remitted to the Council for redetermination.
33. Finely as that argument was put, I am unable to accept it, essentially for the reasons set out in Miss Tafur's compelling submissions.
34. Miss Thomas's submissions were based upon the proposition that the definition of "basement development" in paragraph 34.3.46 (in terms of "the construction or extension of a storey of accommodation…") can be read across to Policy CL7(c), so that the prohibition in that policy provision applies where there has been the earlier, post-July 1948 construction of a storey below prevailing ground level, or the earlier, post-July 1948 extension of such a storey.
35. There is a tenet of construction that, where a term is used more than once in the same formal document (and particularly where it is used more than once in the same section of such a document), it is intended that that term has the same meaning on each usage. However, here, the same term is not used. Paragraph 34.3.46 uses the term "basement development", which it defines in terms of construction or extension of a storey of accommodation below the prevailing ground level. The purpose of that paragraph is to scope Policy CL7, which applies to "all new basement development". Policy CL7(c) does not use the term "basement development". It uses two terms: "basement floors", and simply "basement". In my judgment, "basement" here means "basement floor" (i.e. basement storey), and it is not a reversion back to the different term used in paragraph 34.3.46.
36. In coming to that conclusion, I have particularly taken the following into account.

i) Had the draftsman of Policy CL7(c) intended to convey that which Miss Thomas contends, he could easily have used the term "basement development". He conspicuously did not.

ii) The use of the word "further" before "basement floors" suggests that, when "basement" is used later in that provision, it too is referring to a basement floor or storey. The use of the indefinite article ("… a basement…"), and the reference to "… one built through the exercise of permitted development rights…" (which is a reference back to "a basement"), also suggest that the reference is to a basement floor, not basement development including an extension to a basement.

iii) Although in my view the wording of the policy is tolerably clear on its face, the meaning of Policy CL7(c) becomes abundantly clear when it is considered in context. As I have explained, Policy CL7(b) was the dominant policy, i.e. the prohibition of any new basement development that comprised more than one storey. The rationale for that policy was considered by the Council and the Examiner, and is set out in the policy itself (see paragraph 17 above): it is designed to limit the adverse effects caused by the excavation and construction of basements. Its purpose is not to prevent dwellings having more than one basement storey; but to restrict nuisance to neighbours by proscribing the excavation and construction of more than one such storey. As explained in paragraph 22 above, the overt primary purpose of Policy CL7(c) is to prevent successive applications for cumulative basement storeys, which would frustrate the dominant policy in Policy CL7(b). The Examiner made that clear, and confirmed that it was a sound policy. The focus of Policy CL7(c) on floors (i.e. storeys) therefore furthers the general policy aim.

iv) Miss Thomas points out that, in paragraph 29 of his Report, the Examiner expressly found that "the term 'basement' was [soundly] defined in the Policy at 34.3.46" (see paragraph 20 above). However, I do not see anything in that paragraph of his Report that is inconsistent with the construction which I favour. He does not suggest that he is proceeding on the basis that the definition of "basement" as used in Policy CL7(c) (as opposed to "basement development" as used in paragraph 34.3.46) includes extensions. Indeed, in paragraphs 70-72 of his Report, the Examiner appears to have construed Policy CL7(c) in the way that I favour (see paragraph 22 above). In any event, as I have indicated, the meaning of the policy is ultimately a matter for the court.

37. Therefore, the question posed by Policy CL7(c) is not as Miss Thomas would have it, i.e. whether there is in existence "basement development" as defined in paragraph 34.3.46, which is merely scoping. Policy CL7(c) addressed a second stage question, once it has been determined that the proposed development falls within that scope. Leaving aside any pre-July 1948 construction and any extant but non-implemented permission, the question it raises is, rather, whether a basement (i.e. basement storey) has been built (not merely extended) since July 1948. If the answer to that question is "Yes", then new basement development as defined in paragraph 34.3.46 is proscribed by the policy.
38. Miss Thomas submits that the Planning Officer never brought her mind to bear upon the issues raised by Policy CL7(c); but I am satisfied that she did consider, address and determine the relevant question, as I have formulated it. I accept that some passages to which Miss Thomas referred me are difficult to understand, notably the response to the pre-action letter. However, the Officer's Report specifically deals with whether a basement storey had previously been built at the Property, albeit briefly. In paragraph 7, it deals with consultations responses, including the objection of the Claimant that, "The property already has an extended basement". The Planning Officer responded, as follows:

"The proposed basement would be constructed below the existing lower ground floor level, and would be the first subterranean addition to the property."

As the Planning Officer herself has accepted (in her email of 2 February 2016, referred to in paragraph 32 above), the use of the term "subterranean" is a hangover from the somewhat out-of-date SPD and was in this context not particularly helpful; but "lower ground floor level" as used here is clearly a reference to the particular storey of the house (and not, e.g., the level at which the floor of that storey lies). Whilst not as full or clear as it might be, this is an indication that the Planning Officer was, at the time of her Report, addressing the right question.

39. She confirms that that was the case in her evidence for this claim, in which she also explains how she used "subterranean" in her Officer's Report. In her statement dated 1 April 2016, having set out the substance of Policy CL7(c), she continues:

"13. In exercising my planning judgment I concluded that the previous extensions to the rear of the property, including the existing conservatory and closet wing, did not constitute the implementation of a planning permission for a basement, or the building of a basement through the exercise of permitted development rights. The existing conservatory is a rear extension to the lowest level of the property at the original floor level. I could not construe the reconstruction of the closet wing nor the construction of the conservatory (either separately or together) as the building of basement. I recorded in the report that the proposed basement development was the first subterranean development at the property, by which I meant that no additional floor had previously been added beneath the original lowest floor level of the property. Therefore, I concluded that the proposed basement development did not conflict with Policy CL7(c). In spite of the representations made by the Claimant, I remain of the view that the previous works to the property are properly characterised as rear extensions, and that they did not constitute to the building or implementation of a basement.

14. The question in this case is whether the previous works to the property resulted in the implementation or building of a basement. I do not consider those works to have constituted the implementation or building of a basement…".

40. Whilst I accept that the post-decision material from the Council is neither clear nor as consistent as it might be, I note that the Planning Officer has maintained a more or less consistent line as to her approach to the construction of Policy CL7(c). Although her email of 2 February 2016 was not expressed as a lawyer might have done, it seems to me that she was there focusing upon the lower ground floor as a storey of the building; which, on the basis of the true construction of the policy, was correct.
41. Of course, any post-decision evidence from a decision-maker is open to the suggestion that it is ex post facto justification, rather than a true recollection of her thinking at the relevant time; but, when the clear explanation in her statement is taken with the succinct response set out in the Officer's Report itself, I am satisfied that, at the time of her report, the Planning Officer did adopt the right approach here.
42. In any event, whilst the works in 1967 and the 1990s each extended the footprint of the Property, neither arguably involved the building of a new basement storey; and so, on the true construction of Policy CL7(c), neither arguably involved "the implemented planning permission for a basement or one built through the exercise of permitted planning rights". Consequently, even if, contrary to my view, the Planning Officer did not apply the correct construction of the policy, she did not arguably err in concluding that Policy CL7(c) did not apply to this application.
43. For those reasons, I do not consider that Miss Thomas has made good her main contention under this ground.
44. Two final points on this ground.
45. First, in the alternative, Miss Tafur submitted that, if Miss Thomas's construction of the policy was right, the earlier works to the closet wing and conservatory did not in any event constitute "basement development" as defined in paragraph 34.3.46. The policy draws a distinction between the prevailing ground level of the site, and the prevailing ground level of the property. It is open to the Council in any particular case to consider that, for any particular case, the latter is the more appropriate. "The prevailing ground level of the property" in this case was the platform at lower ground floor level, which extended out beyond the front and rear elevations, upon which the Property was built. The ground floor level (as a storey) was therefore above the relevant prevailing ground level.
46. As a discrete legal submission, I am not entirely persuaded by that; nor am I persuaded that the Planning Officer actually made that analysis at the time. Given her understanding of the policy and how it should be applied, it would have been odd (and entirely coincidental) if she had.
47. However, there is certainly force in the further alternative submission made by Miss Tafur, based upon the Planning Officer's evidence that, in exercising her planning judgment, in this case she considers the prevailing ground level would be better assessed by reference to the property, not the site; and she considers that level to be the platform, i.e. the floor level of the lower ground floor. Miss Thomas frankly accepted that that analysis and conclusion was open to a decision-maker in this case. There is no good reason to suppose that, if the Planning Officer had considered the matter at the time, she would not have come to the same conclusion for the same reasons as she has now; or that, if remitted, the result would not be the same. It is highly likely that it would. Therefore, even if Miss Thomas had succeeded on the construction argument, I would have denied the Claimant any substantive relief, in any event.
48. Second, Miss Thomas also has an alternative argument. She submitted that, in the 1967 works and 1990s works, the floor level of lower ground floor closet wing and conservatory respectively were slightly lowered from the level they had been previously. There was consequently a new basement level as at each of those dates, such that the Policy in CL7(c) applied.
49. There is no force in this argument, which is based upon evidence (including photographs) from the Claimant that there was a small "step", which he measures to be 2.5mm, between the floor level of the main part of the building and that in the closet wing. There appears to be no evidence of a disparity in floor levels between the main building and the conservatory; and the plans and photographic evidence, seem to belie the contention.
50. In respect of the closet wing, the point having been raised by the Claimant, the Planning Officer revisited the Property on 4 August 2016, and recorded her findings in her statement of 16 August 2016. She found that there was no step between the two parts of the building, but only a timber threshold of 2.5mm in height (paragraph 6). Having considered all of the evidence with some patent care (see paragraphs 6-8), she concluded (at paragraph 9):

"I remain satisfied that the original lowest floor level of the property has not been lowered in order to facilitate the erection of the rear closet wing."

51. Findings of fact by planning decision-makers are notoriously difficult to challenge, the threshold being that of Wednesbury unreasonableness, i.e. legal perversity (see paragraph 57 below). The findings of fact made by the Planning Officer in this context are, quite clearly, unimpeachable. In any event, even if the floor of the lower ground storey had been lowered by an inch in 1967, that would be immaterial in the context of Policy CL7(c), there not arguably having been a basement storey added or indeed any extension downwards of any substance.
52. For those reasons, Ground 1 fails.

Ground 2: Conservation Areas

53. As I have indicated, the Property lies within the Norland Conservation Area, and backs onto the Ladbroke Conservation Area, each of which is a designated heritage asset.
54. Section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 provides that, in the exercise of any planning functions, "special attention shall be paid to the desirability of preserving or enhancing the character and appearance of that area." That is reflected in both the National Planning Policy Framework (e.g. paragraph 131); and, particularly, in Policy CL3 of the Council's Consolidated Local Plan, under which the Council "will require development to preserve or enhance the character and appearance of the conservation area…".
55. Miss Thomas submits that the extensive changes and alterations to the Property which are proposed would impact on the views of the front and rear of the Property, with the appearance in the street scene being affected and significant increased light pollution; and the Planning Officer failed to assess whether the total adverse impact of the development as a whole would preserve the character and appearance of the Norland Conservation Area or the setting of the Ladbroke Conservation Area. As related but distinct sub-grounds, she contends that the Planning Officer made two perverse findings of fact, namely (i) that the closet wings are "isolated features", and (ii) that the proposed alterations at the front of the property to accommodate the double basement and its double height light-well would not be harmful.
56. I can deal with this ground and its sub-grounds shortly. None has any legal merit.
57. As Sullivan J emphasised in R (Newsmith Stainless Limited) v Secretary of State for Environment, Transport and the Regions [2001] EWHC 74 (Admin) at [7], albeit in a slightly different context, challenging findings of fact made by a planning decision-maker is "a difficult obstacle for an applicant to surmount", especially where the decision-maker is exercising planning judgment.
58. With regard to the closet wing, Miss Thomas submitted that the Planning Officer's finding that it was an "isolated feature" was perverse, because the Property is "twinned" by the Claimant's own house, which is (or, originally, was) a mirror-image, and so the maintenance of symmetry was important. The proposed wing is somewhat higher (about 1m) than the current wings of both properties. However, in paragraphs 6.4 and 6.5 of the Officer's Report, the Planning Officer considered this issue, with some care. She noted that the closet wing of No 26 was deeper than that at the Property; and that there was "no regular rhythm of closet wings to the rear of properties in this stretch of Portland Road". She concluded that, "given that closet wings are isolated features to the rear of this stretch of properties, the discrepancy in height of the closet wings of these two adjacent properties would not disrupt a general pattern of closet wing heights". She considered it important that the new wing would in any event be of less height than the main building, and "would remain a subservient addition to the property". It is simply unarguable that the Planning Officer, using her planning judgment, was not entitled to make the findings that she did.
59. Equally, the suggestion that her finding that the proposed alterations to the front of the house would not be harmful is perverse has no weight. In paragraphs 6.10 and 6.11 of her Report, the Planning Officer dealt with the relevant factors (including the fact that 22 Portland Road has a double basement which, in her view, the proposal replicated) with equal care. Miss Thomas submitted that the arrangement at No 22 is different – because there is a wider gap between the house frontage and the street – but the Planning Officer went on a site visit, and would have been aware of any differences on the ground. Despite any differences, she was nevertheless entitled to make the findings that she did.
60. Nor is there any greater merit in the broad ground that the Planning Officer failed to have proper regard to preserving the character or appearance of the conservation areas. Indeed, looking at the Officer's Report fairly, the ground is legally hopeless. The report has marked on its front sheet, "Cons Area"; Policy CL3 is noted as a main planning consideration (paragraph 5.10); "whether the proposals would preserve or enhance the character or appearance of the property and conservation area" is noted as a "decisive issue" (paragraph 6.1); having considered various matters, the Report under the heading "Issues and balancing" concludes that the development "would be unobtrusive additions to the site that would preserve the character or appearance of the conservation area in accordance with statutory requirements" (paragraph 6.24); and, in response to particular consultation comments about the Norland Conservation Area, the report confirms that "the proposals are policy compliant". I appreciate that the Claimant may not agree with the Planning Officer's conclusion; but that conclusion, and the analysis that led to it, are again unimpeachable. This ground – like the sub-grounds under this head – are nothing more than a disagreement with findings of the decision-maker, each involving some measure of planning judgment, on their merits. They do not begin to suggest any error in law.
61. Consequently, each element of Ground 2 also fails.

Conclusion

62. For those reasons, this claim is dismissed.