Persimmon Homes (Thames Valley) Limited v Worthing Borough Council

The main question in this case is whether an inspector who granted planning permission for a large development of housing and other uses in countryside within the setting of a National Park made errors of law when considering relevant local and national planning policy. The court below held that he did, in two ways: first, in failing to deal with the proposal’s conflict with two draft strategic policies in an emerging local plan, and secondly, in misapplying the Government’s policy for development that would affect the setting of a National Park.

With permission granted by Warby L.J., the appellant, Persimmon Homes (Thames Valley) Ltd. (“Persimmon”), appeals against the order of Lang J. dated 1 August 2022, quashing a decision of an inspector appointed by the second respondent, the Secretary of State for Levelling Up, Housing and Communities. The inspector allowed Persimmon’s appeal against the refusal by the first respondent, Worthing Borough Council (“the council”), of outline planning permission for a mixed-use development including 475 dwellings on land to the north-west of the railway station in Goring-by-Sea. The Secretary of State defended the decision in the court below, but has taken no part in the appeal to this court.

The site is about 20 hectares of agricultural land, part of Chatsmore Farm, outside the boundary of the built-up area as defined in the Worthing Core Strategy 2011, in an undeveloped swathe of land between the settlements of Goring-on-Sea to the east and Ferring – in the district of Arun – to the west, and within the setting of the National Park. The railway station, which is within the built-up area, lies immediately to the south-east. The South Downs National Park extends down to the A259 Littlehampton Road, which runs east-west on the northern side of the site. Persimmon’s application for planning permission was submitted to the council in August 2020. The council refused planning permission on 11 March 2021. Persimmon appealed under section 78 of the Town and Country Planning Act 1990. The inspector held an inquiry into that appeal over eight days in January 2022. His decision letter is dated 25 February 2022. The challenge to it was brought by an application under section 288 of the 1990 Act.

There were originally four grounds of challenge. The judge rejected grounds 1 and 3 but upheld grounds 2 and 4. Ground 2 was that the inspector failed to take into account the proposal’s conflict with two emerging policies in the Submission Draft Worthing Local Plan, Policy SS1 and Policy SS4, or to provide adequate reasons for his assessment of it against those two policies. Ground 4 was that he had erred in his consideration of the likely effect of the development on the National Park, in particular the acknowledged harm to its setting, failing to perform his duty under section 11A of the National Parks and Access to Countryside Act 1949, to apply the policy in paragraph 176 of the National Planning Policy Framework (“the NPPF”), and to give adequate reasons for his conclusions on these matters. Permission to appeal was granted against the judge’s decision on each of those two grounds. Persimmon must succeed on both issues if the appeal is to be allowed.

The council refused planning permission for six reasons. Only the first and second reasons are relevant to the issues we have to decide. They stated:

The Worthing Core Strategy was adopted in 2011. Together with the saved policies of the previous local plan, it was, at the time of the challenged decision, the statutory development plan. It identified four areas of open countryside as “long established breaks in development between settlements”. The site was in one of those areas. It had been a designated gap in the West Sussex Structure Plan (2004) and in the previous local plan.

Policy 13 of the core strategy stated, under the heading “The Natural Environment and Landscape Character”:

The draft Worthing Local Plan was submitted for examination in June 2021. Examination hearings were held in November 2021. In December 2021 the local plan inspector sent his initial advice letter to the council, indicating the steps required to make the draft local plan sound and legally compliant. The council’s schedule of main modifications, approved by him, was published about two months after the decision on Persimmon’s appeal, in April 2022. Consultation followed, in April and May 2022. The local plan inspector’s report was published in October 2022. He rejected Persimmon’s contention that the appeal site ought to be allocated. The local plan was eventually adopted by the council in March 2023. It contains 12 major allocations for housing development, for about 1,750 dwellings.

Draft Policy SS1 in the emerging local plan set out the strategy for new development in the borough in the plan period. At the time of the challenged decision it stated:

Draft Policy SS4 related to land outside the boundary of the built-up area. At the time of the challenged decision it stated:

Draft Policy SS5 designated four Green Gaps, including Chatsmore Farm and the Goring-Ferring Gap. At the time of the challenged decision it stated:

Emerging Policy SS6 had designated Local Green Spaces, including Chatsmore Farm. In view of the local plan inspector’s advice in his letter of 9 December 2021 that this policy did not comply with the NPPF, the council did not rely on it at the inquiry into the section 78 appeal.

Under the heading “Determining applications”, paragraphs 48 and 49 of the NPPF state:

Section 11A(2) of the 1949 Act provides:

The Government’s Planning Practice Guidance, as published in July 2019, states in paragraph ID 8-039-20190721 that the duty in section 11A “is relevant in considering development proposals that are situated outside National Parks … but which might have an impact on their setting or protection”.

In a section of the NPPF headed “Conserving and enhancing the natural environment”, paragraph 176 sets out government policy for areas with the highest status of protection, which include National Parks. It states:

In his decision letter the inspector identified three main issues. Two are relevant in these proceedings: first, “whether the appeal site offers an acceptable location for development having regard to local and national planning policy, the need for housing, the Council’s emerging local plan and the effect of the proposed development on local green space”; and second, “the effect of the proposed development on the landscape, including the setting of the South Downs National Park (SDNP)” (paragraph 8).

In a section headed “Location and Local Green Space”, when considering “Existing development plan policy”, the inspector concentrated on Policy 13 of the core strategy. It was, he said, “common ground that the appeal site falls outside the BUAB, is not a previously developed site and would conflict with WCS Policy 13”. Persimmon had argued that Policy 13 was “out of date and should be afforded limited weight” (paragraph 11). But the inspector disagreed. In his view this policy “remains one of the cornerstones of the adopted development plan and … continues to serve a useful planning purpose”. And this was “despite it being intended to meet a significantly lower housing requirement, having been prepared under a different policy background and being primarily protective in nature” (paragraph 15).

On “Housing need” the inspector said that “while the parties disagree on the extent of the shortfall, the Council accepts that it is unable to demonstrate a 5-year housing land supply and will continue to be unable to do so post adoption of the emerging Worthing Local Plan (eLP)” (paragraph 20).

Under the heading “The emerging local plan and prematurity”, he noted that the site was “not designated as a local green space, local or strategic gap and does not currently benefit from any formal protection in planning terms”, and that there was no “policy support for its strategic retention in planning terms as part of the current development plan” (paragraph 22). He then turned to the emerging local plan (in paragraphs 23 to 27):

As for the council’s case on “prematurity”, he said this (in paragraphs 28 to 30):

In his “Summary on location and local green space” he concluded (in paragraphs 32 to 34):

In a section headed “Landscape”, the inspector came to the “Setting of the [National Park] and views from within it”, and said this (in paragraphs 44 to 49):

Under the heading “Localised impacts” he considered the likely effects on local views (paragraphs 50 to 56). He agreed with Persimmon’s assessment of “moderate adverse” effects on views from many of the viewpoints assessed, including Goring Street, but concluded that “the impact on receptors travelling along Littlehampton Road, users of the public footpaths 2121 and 2121-1 … and those using the nearby railway bridge would be substantial adverse” (paragraph 56).

His “Overall conclusions on landscape” were these (in paragraph 57):

In a section headed “Overall Planning Balance” he stated these conclusions on the proposal’s relationship to development plan and emerging local plan policy (in paragraphs 82 and 83):

His conclusion on the likely effect of the proposed development on “visual receptors” was this (in paragraph 84):

He accepted that “Worthing has an exceptional unmet need for housing and that position is unlikely to change in the medium term”, that “the appeal site is well located to the existing built-up area and would make a meaningful contribution to meeting this unmet need”, and “that this should be afforded very significant weight at the uppermost end of the spectrum” (paragraph 87). He also accepted that “the appeal scheme would make a significant contribution to meeting the area’s substantial unmet need for affordable housing”, and that the 190 affordable dwellings proposed “would make a significant contribution to meeting the unmet affordable housing need”, which he gave “very significant weight” (paragraph 88).

Finally on the planning balance, he concluded (in paragraphs 91 and 92):

The judge concluded that the inspector should have taken a similar approach to draft Policy SS1 and draft Policy SS4 as he did to draft Policy SS5, “by assessing the proposal against the emerging development plan, and weighing the conflict in the overall planning balance” (paragraph 94 of the judgment), that “the omission of any proper consideration of Policies SS1 and SS4 was an error on the part of the Inspector”, and “[a]lternatively, … the Inspector failed to provide any, or any adequate, reasons in regard to the assessment of the development against [those two policies], and the weight that he attributed to any conflict” (paragraph 95). These were “the product of a new balancing exercise, carried out in the context of the [NPPF], which balanced current housing needs and environmental considerations in the Borough, and had been the subject of examination by another Inspector”. It was therefore “irrational not to treat them as material considerations, which ought to be considered in reaching a decision” (paragraph 105).

Mr Paul Cairnes K.C., for Persimmon, criticised those conclusions. The inspector had not failed to take account of the two draft policies. The relevant parts of draft Policy SS4 incorporated the strategy in draft Policy SS1, and effectively repeated the existing strategy in Policy 13 of the core strategy. The inspector was obviously well aware of those two draft policies. He mentioned draft Policy SS4 in paragraphs 25 and 27 of his decision letter. And when he referred to Policy 13 and the proposal’s conflict with that policy, he was clearly referring to its conflict with draft Policy SS1 as well. His reasons for concluding as he did in paragraphs 32 to 34 are sufficient and clear.

For the council, Ms Isabella Tafur submitted that the judge’s analysis here was correct.

The principles on which the court will act in a challenge to an inspector’s decision are well established (see, for example, the judgment of Lord Carnwath in Suffolk Coastal District Council v Hopkins Homes Ltd. [2017] UKSC 37, at paragraphs 22 to 26, and the leading judgment in this court in St Modwen Developments Ltd. v Secretary of State for Communities and Local Government [2017] EWCA Civ 1643, [2018] PTSR 746, at paragraphs 6 and 7). Caution is essential. Only if the decision is plainly bad in law will the court intervene. As with planning officers’ reports to committee, it will read an inspector’s decision letter in a straightforward way, with common sense and a tolerance of errors that are not material (see the leading judgment in Mansell v Tonbridge and Malling Borough Council [2017] EWCA Civ 1314, at paragraphs 41 and 42). It will not second-guess the inspector’s exercise of planning judgment. Nor will it look for perfection in his reasons (see the speech of Lord Brown of Eaton-under-Heywood in South Bucks District Council v Porter (No.2) [2004] 1 W.L.R. 1953, at paragraph 36, the speech of Lord Bridge of Harwich in Save Britain’s Heritage v Number 1 Poultry Ltd. [1991] 1 W.L.R. 153, and the leading judgment in this court in East Quayside 12 LLP v The Council of the City of Newcastle Upon Tyne [2023] EWCA Civ 359, at paragraphs 36, 37, 51 and 52).

With those principles in mind, I do not think we can conclude that the inspector fell into error in his handling of the draft policies in the emerging local plan, including Policy SS1 and Policy SS4.

It is clear that the council’s case against Persimmon’s section 78 appeal depended, in part, on the contention that the proposal was in conflict with the spatial strategy of the emerging local plan as well as with the strategy in the development plan itself. The council saw that conflict with the emerging local plan as being, in itself, a substantial factor bearing on the planning merits of the proposed development. This was apparent in the first reason for refusal in its decision notice, in its statement of case, in its evidence at the inquiry and in its closing submissions.

Under section 38(6) of the Planning and Compulsory Purchase Act 2004 decision-makers must determine planning applications and appeals in accordance with the development plan unless material considerations indicate otherwise. As the site of the proposed development lay outside the extant built-up area boundary and the proposal was therefore in conflict with Policy 13 of the core strategy, the statutory presumption here was a decision to refuse planning permission. In the council’s view, the proposal’s conflict with the emerging local plan was a material consideration reinforcing that presumption. But as Ms Tafur submitted, the significance of the proposal’s conflict with the emerging plan as a material consideration was that the draft strategic policies represented a fresh statutory process of development plan-making, and the council had now planned in the light of the present level of housing need, which far exceeded the capacity to meet it.

However, the proposal’s conflict with the strategy embodied in draft Policy SS1 and draft Policy SS4 of the emerging local plan was, in substance, the same allegation as its conflict with Policy 13 of the adopted core strategy. Under both the extant development plan and the corresponding provisions of its emerging successor, the site was protected because it was undeveloped land in the countryside, outside the built-up area boundary. The protection was continuous and equivalent. One can therefore readily infer from the inspector’s conclusions on both the adopted and the draft strategic policies that he saw the strategy in draft Policy SS1 and draft Policy SS4 as being, at least for development proposed outside the built-up area boundary, a replication of the current strategy in Policy 13. On this, they were one and the same strategy. In giving Policy 13 “full weight”, the inspector was, in effect, recognising that continuity. To give it even greater weight because it was now duplicated in the emerging local plan was, in his view, unnecessary and unjustified.

This understanding of the inspector’s assessment is reflected in his observation in paragraph 31 of the decision letter that “the appeal site does not form any part of a designated strategic gap for planning purposes, nor does it benefit from any other specific form of protection in planning policy terms over and above that set out in Policy 13 of the WCS”, and also in his conclusions, in paragraphs 32 and 33, that “the proposal would not materially undermine the strategic balance that the Council is seeking to achieve as part of the eLP”, but also that it “would be in conflict with WCS Policy 13 due to its location on a greenfield site outside the BUAB”, and that Policy 13 “forms one of the cornerstones of the adopted development plan and … should be afforded full weight”. On a fair reading of those conclusions and the relevant parts of the decision letter taken as a whole, I think the inspector did confront the council’s contention that the proposal was contrary not only to the spatial strategy in the adopted core strategy but also to the corresponding strategic policies of the emerging local plan, including both Policy SS1 and Policy SS4 as well as Policy SS5.

I do not see how it can be said that he ignored any part of the strategy set out in these draft policies. There is nothing in the decision letter to suggest he did. It is true that he did not refer expressly to Policy SS1. But that omission does not in itself show any legal error. Policy SS4 was mentioned in the council’s first reason for refusal, but Policy SS1 was not. That is not surprising. Policy SS1 had to be read together with the other strategic policies of the emerging local plan, including Policy SS4 and Policy SS5. The broad strategy described in Policy SS1 was elaborated and amplified in those other policies. And the council’s reliance on Policy SS1 was necessarily implicit in its reference to Policy SS4. These policies went together. They expressed a single and coherent strategy. And that was how the inspector regarded them. In my view, on a fair reading of his decision letter, he did not ignore Policy SS1.

It is understandable that the inspector should concentrate mainly on the proposal’s relationship to draft Policy SS5. That policy had a particular significance to Persimmon’s proposal, because it proposed, as a new provision, the formal designation of an area including the appeal site as a gap between settlements. It therefore called for an assessment of a different kind from the broad strategic objectives in Policy SS1 and Policy SS4, which maintained the strategy in Policy 13 of the core strategy.

Nor did the inspector fail to consider the question of weight. Paragraphs 25 and 27 of the decision letter appear in a passage where he was clearly thinking of government policy in paragraph 48 of the NPPF on the factors governing the weight to be given to “relevant policies in emerging plans”. In paragraph 24 he referred to those factors: the stage of preparation of the emerging plan in question, the extent to which there are unresolved objections and the degree of consistency with the NPPF.

He considered “[t]he emerging local plan and prematurity” together as one sub-issue under a single sub-heading. In my view it made good sense to do so. I recognise that the council’s allegation of conflict with the emerging local plan was not the same point as its contention that the proposal was also objectionable on the grounds of prematurity, which was the subject of a separate reason for refusal in the decision notice. The allegation of prematurity went to the integrity of the council’s plan-making itself. The argument was that the development would be so much in conflict with the strategy of the emerging plan that to grant planning permission for it would undermine that strategy and prejudge the local plan process. The distinction between the question of the weight to be given to conflict with policy in an emerging plan and the question of prematurity is reflected in paragraphs 48 and 49 of the NPPF. The connection, however, lies in the relationship of the proposal to the emerging policies themselves. And that consideration was at the heart of the inspector’s assessment in this part of the decision letter. His conclusions in paragraphs 32 to 34 are not concerned only with the issue of the proposal’s prematurity, but also the alleged conflict with the strategic policies of the emerging local plan, as well as with Policy 13 of the core strategy. And in my view he made no legal error in taking that approach.

I therefore disagree with the judge on this issue. I do not think there is any real doubt about the lawfulness of the inspector’s approach to the draft strategic policies of the emerging local plan on which the council relied. In my view he clearly did take those policies into account, gave weight to the proposal’s conflict with them, and provided proper reasons for his relevant conclusions. Those conclusions show a reasonable and lawful exercise of planning judgment on the evidence and submissions he heard.

In the judge’s view the inspector could not rationally conclude both that there would be “moderate adverse and not significant” harm to views from the National Park, as he did in paragraph 47 of his decision letter, and that there would, however, be no adverse effects at all – if this was what he meant in paragraph 49 (paragraph 153 of the judgment). Given the requirement in paragraph 176 of the NPPF that “great weight should be given to conserving and enhancing landscape and scenic beauty” of the National Park, “any assessed harm should be weighed against the benefits of the proposed development in the overall planning balance”. The inspector had “missed out this step, despite the fact that it was flagged to him” in the council’s evidence and submissions (paragraph 154). He had “failed to give any weight to the moderate adverse effects he found, which was in breach of the policy requirement in paragraph 176 of [the NPPF] to give them “great weight”” (paragraph 155). He had also “failed properly to discharge his duty under section 11A of the 1949 Act … by omitting any consideration of the statutory purpose when conducting the overall planning balance” (paragraph 156). Applying the test in Simplex (GE) Holdings Ltd. v Secretary of State for the Environment (1989) 57 P. & C.R. 306, the judge could not conclude that, if the correct approach had been adopted, the outcome would necessarily have been the same (paragraph 157).

Mr Cairnes submitted that those conclusions were mistaken. In paragraph 47 of his decision letter the inspector had identified harm to certain views but had concluded, as he was entitled to do, that the proposal did not conflict with the policy in paragraph 176 of the NPPF as it applies to the setting of a National Park – because the development was “sensitively located” and would “minimise adverse impacts” on the National Park. The references to harm to “visual receptors” in later paragraphs of the decision letter – in particular, paragraphs 57 and 84 – include the harm the inspector had identified in paragraph 47 and show it was brought into the planning balance. This confirms that the inspector gave “great weight” to the conservation and enhancement of landscape and scenic beauty in the National Park, as the first sentence of paragraph 176 of the NPPF requires. He did not have to use the words “great weight” to demonstrate this, as if they were an incantation. In paragraph 49 of the decision letter, he referred expressly to the policy in paragraph 176 of the NPPF, and it was clear he was well aware of what that paragraph said. As the Court of Appeal had accepted in Bayliss v Secretary of State for Communities and Local Government [2014] EWCA Civ 347, giving “great weight” to harm to a National Park under that policy does not compel a decision-maker to give it any specific level of weight in a particular case. There was a range of weight that could be attributed to the harm, as a matter of planning judgment. Here, the inspector obviously concluded that the weight was of no significance.

Again, Ms Tafur argued that the judge was right to conclude that this ground of challenge was well founded, essentially for the reasons she gave.

I agree. I think the judge was right on this ground. At least, in my view, the inspector’s reasons fell short of what was required in law. They leave a substantial doubt about the lawfulness of his approach to one of the principal issues he had to resolve. And that is enough to require his decision to be set aside.

As is common ground, the effect of the proposed development on the setting of the South Downs National Park was not a peripheral matter in the section 78 appeal. It was a prominent aspect of the council’s first reason for refusal. It was part of the second main issue identified by the inspector. And it was extensively considered in the evidence on either side at the inquiry.

To approach the issue lawfully the inspector had to understand the policy in paragraph 176 of the current version of the NPPF correctly. To misunderstand the policy would be an error of law (see the judgment of Lord Reed in Tesco Stores Ltd. v Dundee City Council [2012] UKSC 13, at paragraphs 17 to 19). While the court will not interfere with an inspector’s application of a planning policy, which is a matter of planning judgment, it will require the inspector to undertake that exercise on the basis of a legally correct understanding of what the policy means and requires (see the judgment of Lord Carnwath in Suffolk Coastal District Council v Secretary of State for Communities and Local Government [2017] UKSC 37, at paragraphs 22 to 36).

How then should the policy in paragraph 176 be understood? This question has already, in effect, been considered by this court, both in Bayliss and in Monkhill Ltd. v Secretary of State for Housing, Communities and Local Government [2021] EWCA Civ 74; [2021] PTSR 1432 – neither of which was cited to the inspector.

In Bayliss the court was concerned with the predecessor policy in paragraph 115 of the original version of the NPPF, which referred to the concept of “great weight” in very similar terms to the first sentence of paragraph 176 of the present version. The relevant issue concerned the effect of development on an Area of Outstanding Beauty (“AONB”), not a National Park, but the “great weight” concept applied to both – as it does in the present version of the policy. Sir David Keene said (in paragraph 18 of his judgment) that there was no indication in the inspector’s decision letter that he had failed to take account of the policy in paragraph 115. He was “not required to use the words “great weight” as if it were some form of incantation”. This part of the policy “has to be interpreted in the light of the obvious point that the effect of a proposal on an AONB will itself vary: it will vary from case to case; it may be trivial, it may be substantial, it may be major”. Sir David added that “the decision maker is entitled to attach different weights to this factor depending upon the degree of harmful impact anticipated”; that in his view “it would be irrational to do otherwise”; and that “[t]he adjective “great” in the term “great weight” therefore does not take one very far”. He did not suggest, however, that there might be a level of harm to an AONB or National Park, or to its setting, which might not even engage the application of the policy at all. Applying the policy in a particular case would require the decision-maker to consider the appropriate degree of weight to give to the level of harm he found, conscious of the Government’s policy that “great weight” is to be given to the conservation and enhancement of landscape and scenic beauty in these areas with the highest status of protection.

In Monkhill the court was not directly concerned with the meaning of the expression “great weight”. It was concerned with the question of whether that part of the policy could provide a clear reason for the refusal of planning permission, within the scope of the policy for the presumption in favour of sustainable development in paragraph 11(d) of the NPPF. But the court recognised that, the “real sense” of the policy was “an expectation that the decision will be in favour of the protection of the “landscape and scenic beauty” of an AONB, or against harm to that interest”. Thus, “[i]f the effects on the [Area of Outstanding Natural Beauty] would be slight, so that its highly protected status would not be significantly harmed, the expectation might … be overcome”, or “it might be overcome if the effects of the development would be greater, but its benefits substantial”. This “will always depend on the exercise of planning judgment in the circumstances of the individual case” (paragraph 30). The court therefore agreed with what Sir David Keene had said in the passage I have quoted from his judgment in Bayliss (see paragraph 32 of the leading judgment).

It is not in dispute that the requirement to give “great weight” to conserving and enhancing landscape and scenic beauty “in” a National Park extends to proposals for development within the setting of the National Park, and not only to development on sites within it. The policy in paragraph 176 distinguishes between development inside and development outside a National Park. It indicates one approach for the former, another for the latter. But it plainly includes both. And both are to be considered under the “great weight” principle.

We do not have to decide the question, debated in the court below, whether the expression “great weight” in paragraph 176 carries a similar meaning to the expression “considerable importance and weight” in the assessment of harm to heritage assets (see the judgment of Sullivan L.J. in East Northamptonshire District Council v Secretary of State for Communities and Local Government [2104 EWCA Civ 137; [2014] I P. & C.R. 22, at paragraphs 10 and 28). Lang J. left this question undecided. She considered herself bound by the Court of Appeal’s interpretation of the policy in Bayliss (paragraph 138 of her judgment). And I can see no reason to differ from that interpretation. Of course, the context here is not the same as in the legislation that applies to proposals affecting listed buildings or conservation areas. As Cranston J. acknowledged in Howell v Secretary of State for Communities and Local Government [2014] EWHC 3627 (Admin) (at paragraph 46 of his judgment), the duty in section 11A(2) of the 1949 Act to “have regard” to the relevant statutory purposes, and parallel duties elsewhere in the planning legislation, do not impose an obligation as demanding as the duty to “have special regard” to the desirability of preserving a listed building or its setting in section 66(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990.

The crucial question here, however, is not the meaning of the words “great weight” in the first sentence of paragraph 176 of the NPPF, taken in their own context. It is whether, on a fair reading of the relevant parts of the inspector’s decision letter, his assessment of the likely effects of this development on the setting of the National Park, in which he appears to have accepted that those effects would indeed be harmful, shows how he gave “great weight” to the conservation and enhancement of the landscape and scenic beauty in the National Park, as the policy in paragraph 176 effectively requires. As was held in Bayliss, he was not obliged to use the words “great weight” or even to refer to the paragraph 176 policy by name. But in my view his assessment did have to demonstrate that he had approached the question of harm to the National Park with the “great weight” principle in mind.

There is no doubt that he did find some level of harm to the setting of the National Park. He did not accept the council’s contention that the effect of the development on views from Highdown Hill would be “substantial adverse” (paragraph 46 of the decision letter). But he agreed with Persimmon’s landscape witness, Mr Self, that “the level of harm would be moderate adverse and not significant” (paragraph 47). He evidently did so because, in the “breath-taking” views from that vantage point, the appeal site was “not prominent”, because the “focus is clearly on the sea” – as the South Downs National Park Authority’s “Viewpoint Characterisation and Analysis Study” states – and because the proposed development “would … be seen in the context of existing development – much of which already extends further north and in closer proximity to the [National Park] than would the proposed development” (paragraph 46).

Two conclusions emerge in paragraph 47 of the decision letter, where the inspector was considering views from Highdown Hill. The first concerns the “Visual magnitude of change” under the “Landscape and Visual Impact Assessment” methodology. Using language drawn from that methodology, he accepted that the development “would result in a clearly perceptible and noticeable change to the existing view”. This equates to a “Moderate” magnitude of change according to the methodology. The inspector went on to say that the views “already include intrusive development which affect the tranquillity from within the [National Park]”, that the site “would be seen within this context”, and that the “[e]xtensive views towards the sea and the sense of tranquillity within this part of the [National Park] would not materially alter”. His second conclusion was that “while … there would be change to the view, … the level of harm would be moderate adverse and not significant”. In paragraph 48 he turned to views from Highdown Rise and Highdown Gardens, finding that the proposed development, though “more noticeable”, would again “be seen within the context of the existing development … and would appear neither overly prominent, visually intrusive or materially affect views towards the sea”.

Mr Cairnes did not submit to us that harm of the kind found by the inspector in paragraph 47 of the decision letter – and also, it seems, in paragraph 48 – was simply to be ignored, or that it did not engage the policy in paragraph 176 of the NPPF. I do not think such a submission would have been credible. In the scale of adverse effects prescribed in the methodology for “Landscape and Visual Impact Assessment”, effects in the “Moderate” category sit only one level below “Substantial”, and above “Slight”, “Negligible” and “Neutral”. The description of a “Moderate” effect is that “[t]he proposals would impact on a view from a medium sensitive receptor … and would be a readily discernible element in the view”.

In paragraph 49 of the decision letter the inspector came to the policy in paragraph 176 of the NPPF. He paraphrased the third sentence of paragraph 176, referring to the requirement that development in the setting of a National Park “should be sensitively located and designed to avoid or minimise adverse impacts”. He then concluded, it seems, that the proposal was consistent with that part of the policy, because it would be located at the southern end of the site and because of “the limited impact on views from within [the National Park]”. He did not say whether the effect of those two considerations was to “avoid” adverse impacts or to “minimise” them. What he said was that he did not “therefore” consider that the setting of the National Park or views within it “would be materially affected”.

It is only in paragraph 49 that the inspector addressed the question of the proposal’s compliance or otherwise with the policy in paragraph 176 of the NPPF. In that paragraph, however, he said nothing about the requirement in the first sentence of paragraph 176 that “[g]reat weight should be given to conserving and enhancing landscape and scenic beauty in National Parks”. There are two difficulties here. First, it is not clear how the inspector reconciled his conclusions on harm in paragraphs 47 and 48 with his conclusion at the end of paragraph 49 that neither the setting of the National Park nor views from within it would be “materially affected”. On a straightforward reading of what he did say, these conclusions seem at variance with each other, or at the very least to call for some further words to align them. Secondly, and anyway, it is not clear how he reconciled his conclusions on harm to the setting of the National Park in paragraphs 47 and 48 with the “great weight” principle in the first sentence of paragraph 176 of the NPPF. In what he did say about that harm there is no indication that he gave it such weight as the “great weight” principle required, or indeed what weight, if any, that was. If it really was no weight, he did not explain why this was so.

A third difficulty is this. The conclusions in subsequent passages of the decision letter, including the section where the inspector weighed the planning balance, do nothing to overcome the deficiencies in the passage where he was specifically considering the relationship of the proposal to the policy in paragraph 176 of the NPPF. His “Overall conclusions on landscape” in paragraph 57 of the decision letter repeat his earlier conclusion, in paragraph 49, that the proposed development would not “materially affect the setting of the [National Park]”, but they do not refer to the policy or expand on what he said in paragraph 49. I do not think one can infer that when he said the appeal site was “valued by the local community and … its loss would result in some harm in this respect” he was referring to the effects it would have on the setting of the National Park or to the paragraph 176 policy. And I do not accept he was doing that when he referred to his conclusion that the development would “adversely impact on a number of visual receptors which would result in some further harm”. His references to “visual receptors” in paragraph 57 and again in paragraph 84 seem to relate to his consideration of “localised impacts” in paragraphs 50 to 56, and not to his evaluation of the effects on the setting of the National Park. If this is a misreading of his conclusions, that is, I think, only a consequence of the deficiency in his reasons. And when he came to the “Overall Planning Balance” in paragraphs 82 to 92 he made no mention at all of the National Park and its setting, or of the policy in paragraph 176 of the NPPF. The most one could say is that in acknowledging the development “would result in a number of adverse impacts”, in paragraph 91, he might have meant to include the adverse effects he had found it would have on the setting of the National Park. But this too is unclear.

We do not have to go as far as the judge and find that the inspector’s conclusion in paragraph 49 of the decision letter was, on its face, irrational. It is enough to conclude, as I think we must, that in this part of his decision-making the reasons he gave failed to meet the standard required. Even for an audience familiar with this “principal important controversial [issue]” – as Lord Brown put it in South Bucks District Council v Porter (No.2) (at paragraph 36) – and with the parties’ evidence and submissions about the effects of the development on the setting of the National Park, it is not clear how, or even if, the inspector has resolved that controversy. It is not clear whether he gave any weight, or conceivably no weight at all, to the harm he identified in paragraph 47 of the decision letter. And it is not clear how that degree of weight can be reconciled with the whole policy in paragraph 176 of the NPPF, including the requirement to give “great weight” to “conserving and enhancing landscape and scenic beauty in National Parks”.

Clarity on those matters is not too much to expect of the reasons given on one of the main issues in the section 78 appeal. The level of harm identified by the inspector in paragraph 47 of the decision letter – “moderate adverse and not significant” – was not merely negligible. And it is not obvious how that finding of harm can be squared with the conclusion in the final sentence of paragraph 49 that the setting of the National Park would not be “materially affected”. Even if those two conclusions could be regarded as consistent with each other, it would still be unclear whether the harm identified by the inspector carried any weight in his planning balance, or, if it did, how that amount of weight could be seen as compatible with the “great weight” principle in the Government’s planning policy for National Parks. That is unclear in paragraph 49 of the decision letter. It remains so in paragraph 57, and in paragraphs 82 to 92. I accept that the inspector did not have to voice the words “great weight”, but he did have to show how he had applied that part of the paragraph 176 policy, and how it had influenced the planning balance, if it did.

In my view, therefore, the council’s complaint on this ground is justified. The inspector’s reasons are defective. They leave a substantial doubt that he has lawfully applied relevant national policy to one of the main issues in the section 78 appeal.

Like the judge, I am unable to conclude that relief should be withheld on the basis of the principle in Simplex. It is, in my view, impossible to say that if the inspector had not erred in the way he did his decision would necessarily have been the same.

For the reasons I have given, I would dismiss the appeal.

I agree.

I also agree.