Abdul Sattar v The Secretary of State for Housing, Communities and Local Government & Anor [2026] EWHC 1825 (Admin)

[2026] EWHC 1825 (Admin)Case No AC-2025-LON-000940
IN THE HIGH COURT OF JUSTICE
KING'S BENCH DIVISION
ADMINISTRATIVE COURT
PLANNING COURT
Venue Royal Courts of Justice, Strand, London, WC2A 2LLDate 10 June 2026
Before
HHJ KAREN WALDEN-SMITH sitting as a Judge of the High Court
Between
ABDUL SATTARClaimant(1) THE SECRETARY OF STATE FOR HOUSING, COMMUNITIES AND LOCAL GOVERNMENTDefendants(2) ROYAL BOROUGH OF WINDSOR AND MAIDENHEADDefendant
ROWAN CLAPP (instructed by DMH Stallard LLP) for ClaimantBEN FULLBROOK (instructed by GOVERNMENT LEGAL DEPARTMENT) for DefendantHearing Hearing date: 19 March 2026
Approved JudgmentThis judgment was handed down remotely at 2.30pm on 10 June 2026 by circulation to the parties or their representatives by e-mail and by release to the National Archives..............................

HHJ Karen Walden-Smith:

[1]The claimant challenges the decision of the Secretary of State for Housing, Communities and Local Government (“the Secretary of State”) pursuant to the provisions of section 288 of the Town and Country Planning Act 1990.[2]By his decision promulgated on 14 February 2025, the Inspector appointed by the Secretary of State dismissed an appeal against a refusal of planning permission made by the Second Defendant, the Royal Borough of Windsor and Maidenhead (“RB of Windsor & Maidenhead”), for retrospective planning permission for the retention of a roof extension and alterations to an existing garage at the claimant’s property (“the Development”) on land at Oakley Cottage, Oakley Green Road, Windsor SL4 4QF (“the Development Site”). The Development Site falls entirely within the Green Belt.[3]The issues that the claimant argues are that: Ground 1A(i) The Inspector wrongly considered that he was unable to have regard to Green Belt Purposes and Green Belt Openness for the purpose of determining whether development was proportionate for the purposes of paragraph 154 (c) of the National Planning Policy Framework (“NPPF”);(ii) The Inspector failed to identify whether any harm beyond definitional harm to the Green Belt arose by reason of the Development; Ground 1B(iii) The Inspector failed to identify correctly and therefore weigh harm in the Green Belt against the benefits of the scheme in conducting the “very special circumstances” balance; Ground 2(iv) Inadequate reasons were given in the Decision Letter sent on 14 February 2025. The claimant contends that the Decision Letter did not enable him to understand why the works performed to the garage at the Development Site do not amount to partial redevelopment for the purposes of paragraph 154(g) of the NPPF. The claimant further contends that the Decision Letter fails to provide sufficient information to enable him to understand how the definitional, or other, harm to the Green Belt caused by the Development was not clearly outweighed by the substantial benefits of the Development.[4]The Secretary of State contends that these grounds cannot succeed. Ground 1A(i) The Secretary of State contends that the claimant is wrong to suggest that in deciding whether the Development amounted to a proportionate addition beyond the size of the original building, the Inspector was obliged to consider any effects of the Development on Green Belt openness and the purposes of the Green Belt. The Secretary of State contends that there is Court of Appeal authority which is directly against that submission, and that Green Belt openness and Green Belt purposes are not relevant; Ground 1B(ii) The Secretary of State contends that the alleged failures of the Inspector when balancing harm against the benefit of the Development adds nothing to the first part of Ground 1 and should be dismissed for the same reason of irrelevance as Ground 1A; Ground 2(iii) The Secretary of State contends that the reasoning provided by the Inspector in his Decision Letter easily meets the legal requirements for the purpose of providing reasons in a decision letter.

Permission

[5]Permission to apply for statutory review was initially refused on the papers by Robert Palmer KC sitting as a Deputy High Court Judge on 19 September 2025. Permission for statutory review was granted on all the above grounds by Tim Smith sitting as a Deputy High Court Judge on13 November 2025.

Representation

[6]I am extremely grateful to both Counsel for the claimant, Mr Rowan Clapp and Counsel for the first defendant, the Secretary of State, Mr Ben Fulbrook for their full and well considered oral and written submissions. The second defendant, the RB of Windsor and Maidenhead, did not take part in these proceedings.

The Factual Matrix

[7]The Development is the garage loft conversion at the Development Site, which involved raising the ridge and eaves of the garage alongside a two-storey rear extension with four dormers and alterations to fenestration. The Development Site itself is a long, rectangular parcel of land which includes Oakley Cottage, the dwellinghouse, a garage, a pool/gym pavilion, stables and a tennis court. I have seen both the Site Location Plan and the Elevation Drawings (including the North (Front) Elevation), which show how these various constructions interrelate at the Development Site. I have also seen the report from the claimant’s architects, Heritage & Architecture Chartered Architects, which includes a photograph of the neighbouring property – Wychelms – a property to the west of the Development Site and which is said to assist in showing the established character and appearance of the area.[8]In order to carry out the Development, the roof of the existing garage and existing rear wall had to be removed in order that the rear wall could be extended to the south. The new roof and the replacement rear wall were then constructed.[9]The Inspector set out in the Decision Letter details from the claimant’s “to whom it may concern” document dated 2 May 2024. This included information that the claimant is the founder and managing director of Comfort Care Services Ltd which was founded in 1985 as a specialist care organisation providing supported housing across the south-east of England for vulnerable adults with complex mental health needs which could also involve challenging behaviour, learning disabilities and those recovering from substance and alcohol abuse.[10]The Decision Letter recorded (paragraph 17) that when the pandemic struck in 2020 the company had around 500 patients or clients and around 1,000 staff and that “there was a need to maintain continuity of care in a very challenging situation. Given his role the appellant needed to create desk space for himself and his PA to facilitate home working and to hold meetings with senior managers. This area needed to be kept separate from his family accommodation in order to minimise the risk of spreading the infection. The work to create a home office above the existing garage was undertaken in mid-2020.”[11]The Decision Letter (paragraph 18) further set out that the company had a “vastly superior record to the national average” in the health care sector and that the claimant believed that the creation of an emergency home office saved lives during that time. The Inspector noted that there was no specific evidence as to his role in this respect or why meetings could not have been held online, but it was a highly significant consideration. Further (paragraph 19) while the Inspector records that it is not explained why the office was built over the garage rather than (say) with the construction of a separate outbuilding within the extensive grounds of the property “That said, it was a time of national crisis when actions had to be taken quickly to try and protect people from the effects of a contagious disease. Although that extremely perilous situation has passed the enlarged garage remains. However, the rationale for undertaking the works is largely persuasive and attracts substantial weight in support of the proposal.” The claimant’s case is that by re-organising the business in the way that he did, he was able to develop his care business appropriately.[12]The retrospective application for planning permission was made on 10 January 2024 by the claimant’s architects – Heritage & Architecture Chartered Architects – and received on 22 January 2024.[13]The application for retrospective permission was based upon the development falling within one of the exceptions contained in paragraph 154 of the NPPF which provides that “Development in the Green Belt is inappropriate unless one of the following exceptions applies …”. The claimant relied upon the Development falling within paragraph 154(c) - the extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building and/or paragraph 154(g) - limited infilling or the partial or complete redevelopment of previously developed land (including a material change of use to residential or mixed use including residential), whether redundant or in continuing use (excluding temporary buildings), which would not cause substantial harm to the openness of the Green Belt.[14]The application was refused by the RB of Windsor & Maidenhead on 18 March 2024.[15]That decision was appealed on 6 August 2024. A site visit was undertaken by the Inspector appointed by the Secretary of State on 10 February 2025 and the decision promulgated on 14 February 2025.

The Decision Letter – 14 February 2025

[16]The Decision Letter set out that the works to alter and extend the garage had already been undertaken and that the main issues were:(i) Whether the works were an inappropriate development in the Green Belt having regard to national and local policy;(ii) If so, whether other considerations clearly outweigh the harm to the Green Belt and any other harm so as to amount to very special circumstances.[17]The appeal was dismissed on the basis that the Development amounted to inappropriate development in the Green Belt, which would lead to a loss of openness which was not justified by very special circumstances.

The section 288 challenge

[18]The standard of reasoning provided in a Decision Letter must fulfil the requirements set out by Lord Brown in South Bucks v DC Porter [2004] UKHL 33: the decision must be such that it enables the appellant to understand on what grounds the appeal has been decided and in sufficient detail to enable him to know what conclusion the inspector has reached on the principal important controversial issues. Sir Thomas Bingham MR in Clarke Homes Ltd v Secretary of State for the Environment (1993) 66 P&CR set out that, when identifying whether the central issues regarding reasons have been set out:
“whether the decision of the Secretary of State leaves room for genuine as opposed to forensic doubt as to what he decided and why.”
[19]The challenge to the Decision Letter brought by the claimant must be considered against the principles summarised by Lindblom LJ (as he then was) in St Modwen Limited v Secretary of State for Communities and Local Government [2017] EWCA Civ 164. [The quotation below does not refer to every case cited by Lindblom LJ]:
“In my judgment at first instance in Bloor Homes East Midlands Ltd. v Secretary of State for Communities and Local Government [2014] EWHC 754 (Admin) (at paragraph 19) I set out the ‘seven familiar principles’ that will guide the court in handling a challenge under section 288. This case, like many others now coming before the Planning Court and this court too, calls for those principles to be stated again—and reinforced. They are: (1) Decisions of the Secretary of State and his inspectors in appeals against the refusal of planning permission are to be construed in a reasonably flexible way. Decision letters are written principally for parties who know what the issues between them are and what evidence and argument has been deployed on those issues. An inspector does not need to “rehearse every argument relating to each matter in every paragraph” (2) The reasons for an appeal decision must be intelligible and adequate, enabling one to understand why the appeal was decided as it was and what conclusions were reached on the “principal important controversial issues”
. An inspector’s reasoning must not give rise to a substantial doubt as to whether he went wrong in law, for example by misunderstanding a relevant policy or by failing to reach a rational decision on relevant grounds. But the reasons need refer only to the main issues in the dispute, not to every material consideration. (see the speech of Lord Brown of Eaton-under-Heywood in South Bucks). (3) The weight to be attached to any material consideration and all matters of planning judgment are within the exclusive jurisdiction of the decision-maker. They are not for the court. A local planning authority determining an application for planning permission is free, “provided that it does not lapse into Wednesbury irrationality” to give material considerations “whatever weight [it] thinks fit or no weight at all” (4) Planning policies are not statutory or contractual provisions and should not be construed as if they were. The proper interpretation of planning policy is ultimately a matter of law for the court. The application of relevant policy is for the decision-maker. But statements of policy are to be interpreted objectively by the court in accordance with the language used and in its proper context. A failure properly to understand and apply relevant policy will constitute a failure to have regard to a material consideration, or will amount to having regard to an immaterial consideration. (5) When it is suggested that an inspector has failed to grasp a relevant policy one must look at what he thought the important planning issues were and decide whether it appears from the way he dealt with them that he must have misunderstood the policy in question. (6) Because it is reasonable to assume that national planning policy is familiar to the Secretary of State and his inspectors, the fact that a particular policy is not mentioned in the decision letter does not necessarily mean that it has been ignored. (7) Consistency in decision-making is important both to developers and local planning authorities, because it serves to maintain public confidence in the operation of the development control system. But it is not a principle of law that like cases must always be decided alike. An inspector must exercise his own judgment on this question, if it arises.”[20]Developing on that principle of consistency – set out in sub-paragraph (7) in St Modwen, the courts’ proper respect to the decisions of Planning Inspectors who are experts in planning and, while it is appropriate and necessary for judges to analyse the interpretation of policy, the application of the policy as a matter of planning judgment is for the Inspector and not to be interfered with: see Lord Carnwath in Suffolk Coastal District Council v Hopkins Homes Limited [2017] UKSC 37. Further, in Mansell v Tonbridge and Malling BC [2017] EWCA Civ 1314, the court held that planning officers and inspectors are entitled to expect “that both national and local planning policy is as simply and clearly stated as it can be, and also – however well or badly a policy is expressed – that the court’s interpretation of it will be straightforward without undue or elaborate exposition.”[21]An Inspector is not obliged to give reasons for reasons (see SSCLG v Allen [2016] EWCA Civ 767).[22]With respect to the interpretation of planning policy, Lindblom LJ held in Braintree DC v SSCLR [2018] EWCA 610, that:
“The relevant legal principles are clear and uncontentious. They need not be set out at length. The interpretation of planning policy, whether in the development plan or in statements of national policy, is ultimately a matter for the court. When the meaning and effect of a planning policy are contested, the court must avoid the mistake of treating the policy in question as if it had the force or linguistic precision of a statute – which it does not – and must bear in mind that broad statements of policy do not lend themselves to elaborate exegesis. The court’s task is to discern the objective meaning of the policy as it is written, having regard to the context in which the policy sits.”

The Inspector’s Analysis

[23]In Warwick DC v SSLUHC [2022] EWHC 2145 (Admin), Eyre J. held that whether the new building was, or was not, an extension to the existing building, it is a matter of fact and degree. It is necessary to have regard to the proximity of the new building to the existing building, the purpose and use of the buildings and to factors such as the size of the buildings, and whether the new building was or was not an extension to the existing building. On this basis, the Inspector found it was reasonable to treat the works undertaken as an extension to the dwelling as a whole. The Inspector recorded that the claimant gave the overall floorspace figure for the dwelling of 2,046 sq m. (including a stable building which needed to be discounted). The RB of Windsor & Maidenhead provided that the original floor area of the dwelling was 187 sq m. and that the dwelling had been extended following permission in 1979 for a second floor - creating a further 68 sq m and a conservatory in 2001, which was a further 25 sq m. While he did not expressly do this it appears that the Inspector added those two figures together which gives 93 sq m. or, as said by the Inspector, an extension of the floor area of the dwelling by 50%. The previous garage building and wine store (measuring 72 sq m.) and the pool house (114 sq m.) had nothing to indicate that they were part of the original building. From the claimant’s figures, the Inspector recorded that the Development included an extension to the rear of the garage of 19 sq m. and a usable first floor area of 39 sq m. and, even leaving the pool house building out of the calculation, there had been an overall increase in floor area of 223 sq m which was more than double the size of the original building:
“it provides a clear indication that the development carried out over the years, including the proposal, comprise disproportionate additions.”
The Inspector found (paragraph 9) that judged in percentage terms, the garage development was a 80% increase in floorspace compared to the original garage but, as it included an internal office area, that was slightly misleading:
“However, having regard to the increase in visual bulk brought about by the reconfiguration of the roof and the addition of dormers, the proposal cannot be described as proportionate to the original building. Therefore, even when assessed using the previous garage as the starting point, the outcome is also that the works are disproportionate.”
It appears that the previous garage building and wine store was 72 sq m. The extension added 19 sq m. to the rear and an additional floor area of 39 sq m. – a total addition of 58 sq m.[24]This analysis is criticised by the claimant on the basis that paragraph 154 (c) creates an exception where the development is an extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building. The claimant contends that the Inspector was wrong to concentrate on the alteration in the size of the garage as that was not the original building. The Inspector himself says that there is nothing to indicate that the garage building and wine store were part of the original building (paragraph 7). The original floor area of the property was 187 sq. m. (paragraph 6).[25]The Inspector set out in paragraph 10 the following reasoning:
“The exception specified in paragraph 154 (c) of the Framework makes no mention of Green Belt openness or the five purposes listed in paragraph 143. They are therefore not relevant when undertaking this exercise. The judgment in R (on the application of Samuel Smith Old Brewery (Tadcaster)(Respondents)) and others) v North Yorkshire County Council (Appellant) [2020] UKSC 3 was concerned with the meaning of openness and therefore does not assist in deciding whether the development undertaken is disproportionate or not.”
[26]The Inspector therefore confirmed that he was not going to consider the five purposes set out in paragraph 143 of the NPFF or have regard to Green Belt openness when considering whether the paragraph 154(c) exception has been made out. The Inspector found that the proposal resulted in a disproportionate addition to the size of the original building and was therefore inappropriate development and further that “the effect on the overall openness of the Green Belt is very limited given its relatively small increase in size and the consequent visual implications.” (paragraph 15).[27]The Inspector further took into account that the Planning Officer of RB Windsor and Maidenhead had acknowledged that the proposal causes no other harms and does not breach relevant policies unrelated to the Green Belt but found that the “absence of objection in other respects is not a positive factor that weighs in favour.” (paragraph 16) The Inspector also set out the background to the development (as is set out above) and said that the creation of an emergency office saved lives during that time which is clearly a highly significant consideration and that the rationale for undertaking the works is largely persuasive and attracts substantial weight in support of the proposal (paragraphs 17 to 19).[28]Under the heading “final balance”, the Inspector found that the proposal is an inappropriate development within the Green Belt and that in accordance with the NPPF substantial weight should be given to any harm to the Green Belt. He found that there was a very limited reduction in openness but the need to protect employees and those cared for by the claimant’s company is a matter of substantial weight.[29]Finally, the Inspector said that there are powerful forces on both sides, and in order for very special circumstances to exist the other considerations need to clearly outweigh the totality of harm. “The essential health care work facilitated by the proposal does not cross that high threshold and so there are not very special circumstances which justify accepting the proposal.”(see paragraph 21).[30]With respect to the claimant’s reliance on the exception set out in paragraph 154(g), this was only referred to in one paragraph of the decision letter at paragraph 12, finding that the exception did not apply because “the proposal does not involve partial or complete redevelopment.”

Legal and Policy Framework

[31]In paragraph 4 of his Decision Letter, the Inspector notes that policy QP5 of the RB of Windsor & Maidenhead Borough Local Plan applies national Green Belt policy to its rural areas. The rural areas in the RB of Windsor & Maidenhead are defined as land within the Metropolitan Green Belt, including those settlements that are ‘washed over’ by the Green Belt, which includes Oakley Green – where the Development Site is located.[32]The national Green Belt policy is set out in Chapter 13 of the NPPF, which provides:
“142. The Government attaches great importance to Green Belts. The fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open; the essential characteristics of Green Belts are their openness and their permanence. 143. Green Belt serves five purposes: a) to check the unrestricted sprawl of large built-up areas; b) to prevent neighbouring towns merging into one another; c) to assist in safeguarding the countryside from encroachment; d) to preserve the setting and special character of historic towns; and e) to assist in urban regeneration, by encouraging the recycling of derelict and other urban land.”
[33]Paragraph 153 of Chapter 13 of the NPPF provides that:
“When considering any planning application, local planning authorities should ensure that substantial weight is given to any harm to the Green Belt, including harm to its openness. Inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. ‘Very special circumstances’ will not exist unless the potential harm to the Green Belt by reason of inappropriateness, and any other harm resulting from the proposal, is clearly outweighed by other considerations.”
While paragraph 154 of Chapter 13 of the NPFF provides that:
“Development in the Green Belt is inappropriate unless one of the following exceptions applies: … c. the extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building; … g. limited infilling or the partial or complete redevelopment of previously developed land (including a material change of use to residential or mixed use including residential), whether redundant or in continuing use (excluding temporary buildings), which would not cause substantial harm to the openness of the Green Belt.” “Development in the Green Belt is inappropriate unless one of the following exceptions applies: … c. the extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building; … g. limited infilling or the partial or complete redevelopment of previously developed land (including a material change of use to residential or mixed use including residential), whether redundant or in continuing use (excluding temporary buildings), which would not cause substantial harm to the openness of the Green Belt.” 34. There is no material difference between paragraphs 87 to 89 of the NPPF 2012 and the wording of paragraphs 153 to 154 of the current NPPF, and consequently earlier cases dealing with the NPPF 2012 remain relevant to the interpretation of current Green Belt policies. “Original Building” is defined in the Glossary to the NPPF as “Original building: a building as it existed on 1July 1948 or, if constructed after 1 July 1948, as it was built originally.”

The Exceptions

[35]The claimant relies upon a line of authorities to support a purposive interpretation of the “exceptions” set out in paragraph 154 of the NPPF to better perform their purpose of limiting harm to the Green Belt, with the need to examine the underlying purpose of the exception and not to overlook the purpose and objective of policy that is being applied.[36]In Tandridge DC v SSCLG [2015] EWHC 2503 (Admin), David Elvin KC (sitting as a Deputy High Court Judge) considered the question of how to interpret bullet four of paragraph 89 of the NPPF 2012, the forerunner to paragraph 154(d). The issue was how to interpret “building”. An Inspector had determined that the term “building” could apply to a group of buildings being replaced by one building, whereas the claimant was contending that the term “building” meant that the proposed new building should only be compared with a single existing building. David Elvin KC found that the term “building” was to be interpreted as follows:
“this term, and its role as an exception to the general principle that new buildings are inappropriate development in the Green Belt, should be considered in its context of the NPPF as a whole and in the context of the Green Belt policies in particular.”
Interpretation of paragraph 154 needs to be on the basis of its purpose, which is to protect Green Belt openness and the other Green Belt policies. As David Elvin said in Tandridge:
“linguistic analysis will only take the interpretation of the exception so far, since it is also necessary to examine the underlying purpose of the exception” and “it is necessary not to overlook the purpose and objective of policy that is being applied and to consider that purpose when applying the policy to the individual facts of the case.”
[37]It was held in Tandridge that the thrust of the exception was to “recognise that a replacement may be made because of the existence of buildings in the Green Belt which already have some effect on the openness of the Green Belt.” The reason for the “not materially larger” test is to confine the extent to which the replacement may differ in scale from that which it replaces.” David Elvin further found that “the exceptions to the general inappropriateness of new building in the Green Belt are generally expressed restrictively in order to limit the impact on openness.” Based on Tandridge, interpretation should be conducted with that purpose in mind.[38]In Tandridge, the claimant relied upon there being no reference to the effect of openness on the Green Belt within the equivalent of paragraph 154(d), while some other exceptions referred to openness expressly. “In my judgment, the explicit reference to openness in the second and sixth exceptions in paragraph 89 is not a contraindication to its being the underlying purpose of the fourth exception but merely that in the cases of the second and sixth exceptions, the exceptions are not dealing with the extension, alteration or replacement of existing buildings which provide the baseline for testing their acceptability and the acceptability of proposals, but with proposals without such baselines where it is necessary to consider their effect on openness. If anything, the explicit reference in those cases underlines the fact that it is implicit in exceptions 3 and 4. The fifth of the exceptions allows for provision to be made in local plans where doubtless consideration will be given to the issue of openness the policies are set. The first exception is simply dealing with agricultural and forestry operations which are doubtless considered consistent with the openness of the Green Belt.”[39]The exceptions in paragraph 154(c) and paragraph 154 (d) of the NPPF, achieve the underlying purpose of preserving Green Belt openness by requiring the extension, alteration or replacement of existing buildings to be tested against the baseline provided by the existing building not by the Inspector being required to answer the question of whether the development harms Green Belt openness or purposes. In any event, the decision of the Court of Appeal in R(Lee Valley Regional Park Authority) v Epping Forest DC [2016] Env LR 30 (referred to in greater detail below) sets out the principles to be applied. In Warwick v SSLUHC, referred to by the Inspector in his Decision Letter, Eyre J set out the importance of the construction of paragraph 149 of Chapter 13 of the NPPF to be “narrow but not artificial” and that “as with statements of planning policy more generally the meaning of the exceptions is to be derived from the languages used when seen in the context of the subject matter and the purpose of the policy in accord with the principles summarised by Dove J. and set out above. Here the context and purpose are to be seen as the importance of the Green Belt and the purposes which they serve … having regard to the particular points that inappropriate development is by definition harmful to the Green Belt and that the construction of new buildings is inappropriate to development unless within one or more of the exceptions.” Eyre J further referred to the purpose of the exception operating to “provide protection for the purposes of the Green Belt”.[40]In R(Heath and Hampstead Society) v Camden LBC [2008] 2 P & CR 13, Carnwath LJ (as he then was) approved the approach that had been taken by

the judge in Surrey Homes Limited v Secretary of State for Environment (2001):

“As the Deputy Judge held in the Surrey Homes case, even the issue of “not materially larger” does not always depend simply on a floor space comparison but must also be judged by reference to other factors which might affect openness: “23… In most cases floor space will undoubtedly be the starting point, if indeed it is not the most important criterion. But I entertain no doubt that the concept of whether a dwelling is “materially larger” can be assessed by reference to matters such as bulk, height, mass and prominence. These are all matters going to the openness of the Green Belt. They are plainly all material considerations relevant to deciding on the meaning of the term in the context in which it arises, namely Green Belt policy.” 24. Indeed, were it otherwise, absurd results could arise. One could have equivalent or possibly even reduced floor space, but disposed within a tower-like structure, having far more impact on the Green Belt. It would be a strange result, in my judgment, if an Inspector were debarred from concluding that the proposed structure harmed openness and was inappropriate development.”
The Secretary of State contends that the claimant is wrong to assert that in deciding whether the Development amounted to a proportionate addition over and above the size of the original building, the Inspector was required to consider the effects of the Development on Green Belt openness and the Green Belt purposes. The Secretary of State places reliance upon the determination of Lindblom LJ (as he then was) in Lee Valley. Lindblom LJ was considering the meaning of, what was then, paragraphs 87-89 of the NPPF. The issue he was dealing with was whether the Inspector was entitled to find that buildings for agricultural and forestry were not inappropriate in the Green Belt but were nevertheless harmful to the openness of the Green Belt. Lindblom LJ found that the Inspector was not entitled to find the buildings were not inappropriate but were nevertheless harmful to openness. The Secretary of State contends that his reasoning in Lee Valley is directly relevant to this case. In Lee Valley Lindblom LJ said that the words in the NPPF must not be read in isolation and that in reading the policies together it is clear that “buildings for agriculture and forestry” and other development that is not “inappropriate” in the Green Belt are not to be regarded as being harmful to the openness of the Green Belt or to the purposes of including land within the Green Belt. He held that the distinction between development that is “inappropriate” and development that is not “inappropriate” (i.e. is appropriate) governs the approach a decision-maker must take in determining an application for planning permission. Inappropriate development is, by definition harmful, whereas development in the excepted categories is not. The physical presence of agricultural buildings in the Green Belt is not, in itself, regarded as harmful to the openness of the Green Belt as it is not a matter of planning judgment - that is a matter of policy. Appropriate development is not inimical to the fundamental aim of the Green Belt, or to the essential characteristics of the Green Belt, or to the five purposes served by the Green Belt:
“Thus the real significance of development being appropriate in the Green Belt, and the reason why it does not have to be justified by “very special circumstances.”
[41]As Dove J said (in [61] of his first instance judgment in Lee Valley), the fact that an assessment of openness is “a gateway in some cases to identification of appropriateness” in NPPF policy indicates that “once a particular development is found to be, in principle, appropriate, the question of the impact of the building on openness is no longer an issue”. Implicit in the policy in para.89 of the NPPF is a recognition that agriculture and forestry can only be carried on, and buildings for those activities will have to be constructed, in the countryside, including countryside in the Green Belt. Of course, as a matter of fact, the construction of such buildings in the Green Belt will reduce the amount of Green Belt land without built development upon it. But under NPPF policy, the physical presence of such buildings in the Green Belt is not, in itself, regarded as harmful to the openness of the Green Belt or to the purposes of including land in the Green Belt. This is not a matter of planning judgment. It is simply a matter of policy. Where the development proposed is an agricultural building, neither its status as appropriate development nor the deemed absence of harm to the openness of the Green Belt and to the purposes of including land in the Green Belt depends on the judgment of the decision-maker. Both are inherent in the policy.[42]In R (Mole Valley DC) v SSHCLG [2025] EWHC 2127 (Admin), Choudhury J.

(a) of Chapter 13 of the NPPF:

“the Court’s views were not confined to developments amounting to buildings for agriculture and forestry, but extended to any development that is not inappropriate. I therefore reject Mr Goodman’s submission that the ratio in Lee Valley is confined to the former and that the critical passages in the judgment of the Court of Appeal are “tightly focused” on that category of development.”
[43]The submissions made on behalf of the Secretary of State are that, based upon the determination of Lindblom LJ in Lee Valley, as subsequently interpreted, development which is appropriate in the Green Belt is, by definition not harmful to openness and, conversely, development which is inappropriate for the Green Belt is, by definition, harmful to openness. As a consequence, the primary question for the decision maker is whether development is, or is not, inappropriate. This does not, it is argued, entail any separate consideration of harm to openness or the effect of the development on the purposes of the Green Belt save where that is expressly required – for example, paragraphs 154(b), (g) and (h). Further, it is contended that development which causes no actual harm to the openness or purposes of the Green Belt will still be inappropriate development for the purposes of paragraph 153 as: “there is no general test that development is appropriate provided it preserves the openness of the Green Belt and does not conflict with the purposes of including land within the Green Belt” (per Lindblom LJ)[44]In Doncaster MBC v Secretary of State for the Environment [2002] EWHC 808 (Admin), Sullivan J set out that:
“… the proper question for the Inspector in the present case was whether the harm, by reason of inappropriateness, and the further (albeit limited) harm caused to the openness and purpose of the Green Belt were clearly outweighed by other considerations … … it is very important that full weight is given to the proposition that inappropriate is by definition harmful to the Green Belt. That policy is a reflection of the fact that there may be many applications in the Green Belt where the proposal would be relatively inconspicuous or have a limited effect on the openness of the Green Belt, but if such arguments were to be repeated the cumulative effect of many permissions would destroy the very qualities which underlie Green Belt designation. Hence the importance of recognising at all times that inappropriate development is by definition harmful, then going on to consider whether there will be additional harm by reason of such matters as loss of openness and impact on the function of the Green Belt”
[45]Doncaster was a case dealing with Green Belt policy in PPG2, but I am satisfied that the decision equally applies to Green Belt policy in the NPPF as Lindblom LJ confirmed in Lee Valley that the proper approach to the fundamental principle of Green Belt policy in the NPPF was unchanged from PPG 2. The Challenges Ground 1(a)

The Challenges

[46]The claimant challenges the Inspector’s assessment of proportionality for the purposes of paragraph 154 (c) of the NPFF. It is said on behalf of the claimant that the Inspector’s analysis was flawed when considering whether the Development resulted in a disproportionate addition over and above the size of the original building because he considered both Green Belt openness and the five purposes of the Green Belt were not relevant. In oral submissions, the claimant accepted that it would be wrong in light of Lee Valley to say that Green Belt openness and the five purposes were something that required independent consideration, but it is suggested that the Inspector erred in failing to have regard to Green Belt openness and Green Belt purposes as the words within paragraph 154 (c), including “disproportionate” should be interpreted in that context. The claimant is not, therefore, seeking to suggest that the Inspector was obliged to undertake a two-stage test and to consider, beyond the appropriateness or inappropriateness of the development, whether the Development would harm Green Belt openness or Green Belt purposes.[48]What the claimant contends is that the Inspector shut his mind to the impact on the Green Belt when considering whether the Development was inappropriate, and that he erred by failing to read paragraph 154 (c) in the context of the NPPF as a whole and “more importantly, in light of the purposes of the Green Belt” (Warwick DC). That approach of evaluation of the exception in the wider context of Green Belt openness and Green Belt purposes is supported by the other authorities relied upon by the claimant: Surrey Homes and Tandridge.[49]It is undoubtedly correct that the judgment of the Court of Appeal in Lee Valley establishes that the question of whether a development is appropriate or inappropriate is distinct from the question of Green Belt openness and Green Belt purposes. Whether a development is appropriate or inappropriate is a policy issue, it being determined as a matter of policy that some development within the Green Belt is appropriate as set out in the exceptions in paragraph 154. As a consequence, some developments will be appropriate even though there is harm from the development to Green Belt openness or Green Belt purposes, whereas a development that does not cause harm could be inappropriate.[50]The exceptions set out in paragraph 154 of the NPPF deal with the conflict between Green Belt openness and the Green Belt purposes, and the need for some development on the Green Belt. Within paragraph 154 there are three categories of development that are deemed as not being inappropriate without any proviso (these are the exceptions in paragraphs 154 (a), 154 (e), and 154 (f)); there are three types of development which are deemed to be not inappropriate subject to express provisos about the preservation of openness of the Green Belt and lack of conflict with Green Belt purposes (these are the exceptions in paragraph 154 (b), 154(g) and 154 (h) – where the development which falls within (b) and (h) is deemed to be inappropriate if the development causes any harm, whereas with paragraph 154 (g) the development is deemed inappropriate if it causes substantial harm); and two exceptions where the development is not inappropriate provided that they are not disproportionate to or materially larger than development which already exists (paragraphs 154 (c) and 154 (d)). The wording of the different exceptions indicates deliberate policy choices with respect to what will be considered inappropriate or not inappropriate (appropriate).[51]The claimant suggests that the failure to apply Green Belt purposes could lead to absurd outcomes, but I do not accept that would be the case if the exceptions are applied as set out in paragraph 154 of the NPPF. With respect to paragraph 154 (c), unlike paragraph 154 (g), there is no reference to the “openness of the Green Belt.” The construction of new buildings in the Green Belt is “inappropriate” development unless it falls within one of the exceptions – including that it is an extension or alteration of a building “provided that it does not result in disproportionate additions over and above the size of the original building.”[52]Consequently, if the development is appropriate because it falls within one of the exceptions, it is by definition not harmful to openness. Development which is inappropriate because it falls outside an exception, is harmful to openness. The Inspector’s decision is whether the development is appropriate or not pursuant to the paragraph 154 exceptions. This does not require any further consideration of whether there is harm to the openness of the Green Belt or the effect upon the purposes of the Green Belt. The distinction between appropriate and inappropriate development is a matter of policy and paragraph 154 establishes that, as a matter of policy, some development of existing properties in the Green Belt are not harmful.[53]In paragraph 10 of the Decision Letter, the Inspector sets out that the decision in R (oao Samuel Smith Old Brewery (Tadcaster) and others)(Respondents) v North Yorkshire County Council (Appellant) [2020] UKSC 3, was concerned with the meaning of openness and therefore does not assist in deciding whether the development undertaken is disproportionate or not. He also states that neither Green Belt openness nor the five purposes are relevant. In my judgment, he cannot be criticised for that conclusion. The claimant contends that the Inspector has therefore erred in adopting an unduly narrow interpretation to whether the additions to the building are disproportionate by only carrying out a comparison of numerical size. But that is not correct as in paragraph 9 of the Decision Letter the Inspector expressly refers to the “increase in visual bulk brought about by the re-configuration of the roof and the addition of the dormers” and that, consequently, “the proposal cannot be described as proportionate to the original building.” He does not, as is suggested by the claimant, shut his mind to the impact on openness. The task of the Inspector was to determine whether the Development was disproportionate or not and not to apply the broader test of whether the Development would harm Green Belt openness or the Green Belt purposes. What the Inspector was obliged to do, and what he did, was determine whether the extension or alteration (the Development) when considered alongside the other additions to the original building, was disproportionate to the size of the original building. He found it was.[54]The Inspector was carrying out a planning judgment and was considering the increase of size on the basis of volume and also considering the visual appearance of the increase in size. In paragraph 15 of the Decision Letter, the Inspector referred to “the effect on the overall openness of the Green Belt” as being “very limited given its relatively small increase in size and the consequent visual implications”. In paragraph 20 of the Decision Letter, the Inspector referred to “the effect on the overall openness of the Green Belt is very limited given its relatively small increase in size and the consequent visual implications.” It is therefore clear that the Inspector was not “shutting his mind” when considering proportionality, but he was not required to give specific consideration of the effects on openness or Green Belt purposes (Lee Valley). The fact that the Inspector was not closing his mind to other matters beyond a numerical comparison is further supported by the fact that he expressly set out that “floor area is not the only way to assess the cumulative size of additions relative to the original building” (see paragraph 8).[55]For the reasons set out, the Ground 1(a) challenge must fail.

Ground 1(b)

[56]The claimant contends that the Inspector failed to have regard to the Green Belt purposes and Green Belt openness and dismissed Samuel Smith (Tadcaster) as not assisting in deciding whether the development undertaken is disproportionate or not. It is said that the Inspector only carried out a mathematical exercise and failed to specify what harm above “definitional” harm arose from the Development and whether the limited impact on openness was a material harm. It is said by the claimant that the balancing exercise could not be undertaken without assessing the harm and its impact.[57]The Inspector correctly considered that Policy QP5 of the Local Plan, with respect to the Green Belt, was the key policy and that the NPPF provides that development in the Green Belt is inappropriate unless one of the specified exceptions applies. If one of the specified exceptions does not apply then there must be very special circumstances to exist which “clearly outweigh the totality of harm.” The claimant’s complaint is that it was not possible to say if there are the very special circumstances to clearly outweigh the totality of harm, unless the level of harm is assessed.[58]I do not accept that is a valid criticism as the Inspector makes clear that the high threshold to establish very special circumstances has not been demonstrated and, in those circumstances, the weight to be applied to the harm did not need to be specified. As consequence, the ground 1 (b) challenge must also fail.

Ground 2

[59]The challenge brought under ground 2 is with respect to the claimant’s concern that the Inspector had failed to provide an explanation as to why the Development came within the paragraph 154(g) exception. The only reasoning given was that the Inspector found that the Development “does not involve partial or complete development.” The claimant contends that extensive works of demolition and construction were required to bring the Development about and at least part of the garage had been lost and amended, with both the roof and a wall of the garage being removed and replaced.[60]The claimant contends that the “issue of whether development comprises ‘partial redevelopment’ is necessarily a planning judgment and it was open to the Inspector to find that the Development fell within that definition.” Whether the development forms partial redevelopment, or not, is a matter of planning judgment and the Inspector was entitled to conclude that it did not form partial redevelopment. He answered the issue in a proportionate way to the manner in which the claimant had described the development, namely as “retention of roof extension and alterations to existing garage.”[61]Without any substantive argument advanced by the claimant as to why the development amounted to partial or complete redevelopment of previously developed land which would not cause substantial harm to openness of the Green Belt, the Inspector did not have any further issues that he needed to deal with expressly. He gave the answer to the claimant’s case, and to require him to go further would be compelling him to give “reasons for reasons”. What the Inspector had to do was “make sure that his decision letter shows why the outcome of the appeal was as it was, bearing in mind that the parties to the appeal know well what the issues were.” (per Lindblom LJ in SSCLG v Allen [2016] EWCA Civ 767). As was made clear in the judgment of Holgate J (as he then was) in R (oao Together against Sizewell C Ltd) v Secretary of State for Energy Security and Net Zero [2023] EWHC 1526, the level of reasoning required is dependent upon the argument put forward. An unsubstantiated assertion does not require a more detailed response. Having found that the Development does not involve partial or complete redevelopment there was nothing else for the Inspector to set out and I do not accept that the claimant can properly contend that the Decision Letter “leaves room for genuine as opposed to forensic doubt as to what [the Secretary of State] decided and why “ per Sir Thomas Bingham MR in Clarke Homes Ltd.[62]In all the circumstances, Ground 2 must also fail.[63]Having concluded that all three grounds are not made out, the section 288 challenge fails.