The Chalfont St Peter Green Belt challenge has been launched by Buckinghamshire Council and local campaign group SENSE4CSP against the Secretary of State’s decision allowing up to 975 homes on land at the Epilepsy Society in Chalfont St Peter.
The legal distinction matters. This is not another planning appeal and the High Court is not being asked simply to decide whether the development should go ahead. The claim is a statutory challenge under section 288 of the Town and Country Planning Act 1990, directed at the lawfulness of the Secretary of State’s decision-making process.
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What development did the Secretary of State allow?
The site is land at The National Society for Epilepsy, Chesham Lane, Chalfont St Peter, Buckinghamshire SL9 0RJ. The outline application, reference PL/22/2898/OA, proposed a substantial mixed development including:
- Up to 975 C3 homes, including affordable housing
- Up to 75 C2 care-bed spaces
- A new primary school
- Local retail and employment uses
- Re-provision of sports pitches
- Landscaping, open space, parking and associated infrastructure
The application was made in August 2022. The Epilepsy Society appealed against Buckinghamshire Council’s failure to determine it, so the appeal proceeded on non-determination rather than against a formal refusal notice.
Why was the appeal recovered?
The appeal was recovered for decision by the Secretary of State on 29 August 2025. The Inspector recorded that the recovery reflected both the scale of the residential development and its potential significance for national housing-supply objectives, together with the fact that it involved significant development in the Green Belt.
Planning Inspector Lesley Coffey opened the inquiry on 30 September 2025 and sat for eight days. She recommended that the appeal be allowed and planning permission granted.
On 29 June 2026, the Secretary of State agreed with that recommendation and allowed the appeal. The official recovered appeal decision and Inspector’s report are published by GOV.UK.
This was Green Belt inappropriate development
The decision did not proceed on the basis that the whole site had somehow ceased to be Green Belt, nor did the Secretary of State simply relabel the proposal “grey belt”. The scheme was treated as inappropriate development in the Green Belt.
That matters because inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances. The decision therefore required the familiar balance: Green Belt harm and other identified harms on one side, and the benefits relied upon by the appellant on the other.
Planning Geek’s Green Belt, grey belt, greenfield and brownfield guide explains why those labels should not be treated as interchangeable.
What harms did the decision identify?
The Secretary of State gave substantial weight to the harm to the Green Belt and to landscape and visual harm. Other harms identified in the overall balance included heritage impacts and effects on the setting of the National Landscape.
The exact planning balance is important because a finding of very special circumstances does not make the Green Belt harm disappear. The harm remains in the balance and must be clearly outweighed by the other considerations relied upon.
What benefits carried weight?
The decision gave substantial weight to several benefits, including:
- The business case linked to the future of the Epilepsy Society and its research activities
- Delivery of market housing
- Delivery of affordable housing
- Provision for older people
It also gave significant weight to public-transport and sustainability measures and to the Green Belt “Golden Rules”, with further weight given to biodiversity net gain, self-build/custom-build opportunities and public open space.
Housing supply formed part of the context. The decision recorded a severe shortfall in the relevant housing-land supply evidence, adding weight to the delivery of up to 975 homes.
The Epilepsy Society business case was central
A distinctive element of this appeal was the argument that receipts from the development would support the Epilepsy Society’s charitable and research work. The Inspector and Secretary of State considered evidence about investment in research facilities, clinical and scientific work and the longer-term funding position.
The decision gave the business case substantial weight, with legal obligations used to secure relevant commitments. That benefit formed part of the overall very-special-circumstances balance rather than operating as a free-standing exemption from Green Belt policy.
Why did the Secretary of State find very special circumstances?
Having weighed the case as a whole, the Secretary of State concluded that the Green Belt harm and other harm were clearly outweighed by the combined benefits and other considerations. Very special circumstances were therefore found to exist.
That is the planning judgment now under legal challenge. It is not enough in a section 288 case for the challengers simply to say that they would have struck the balance differently. The question for the court is whether the decision was made lawfully.
What do Buckinghamshire Council and SENSE4CSP say?
Buckinghamshire Council says there are important legal questions about how the decision was made, particularly the way the benefits of the development were balanced against the impact on the Green Belt.
SENSE4CSP, the local campaign group which has opposed major development on the site and participated in the planning process, is bringing the challenge alongside the council. The group has a long history of involvement in development proposals affecting the Epilepsy Society land, including opposition to earlier large-scale proposals in the 2000s.
At the time of writing, the full statement of facts and grounds filed in the High Court does not appear to be publicly available through an authoritative open-access source. It would therefore be wrong to present a detailed list of pleaded grounds as though it had been verified.
Open-access reporting of the council’s statement records its concern about the Green Belt balance. That is the allegation; it should not be confused with a court finding that the Secretary of State made an error.
What does a section 288 challenge actually do?
Section 288 of the Town and Country Planning Act 1990 provides a statutory High Court route for challenging certain planning appeal decisions. Planning Geek’s guide to judicial review and section 288 challenges explains the distinction between the routes.
The court is concerned with lawfulness, not with conducting the planning inquiry again. Depending on the case actually pleaded, public-law issues can include:
- Misinterpretation of planning policy
- Failure to take account of a material consideration
- Taking account of an immaterial consideration
- Inadequate or legally defective reasoning
- Procedural unfairness
- Irrationality, where properly arguable
Those are examples of the kinds of legal issue a statutory challenge may raise. They are not a statement that every one of those grounds has been pleaded by Buckinghamshire Council or SENSE4CSP in this case.
What happens if the challenge succeeds?
Success would not automatically mean that the 975 homes are permanently refused. If the High Court finds a material legal error, it can quash the decision. The planning appeal would then normally have to be reconsidered by the Secretary of State in accordance with the court’s judgment.
That reconsideration could produce a different result, but it could also lawfully produce the same result after the identified error had been corrected. Buckinghamshire Council itself has acknowledged that possibility.
Our planning appeals guide explains the ordinary appeal process, while our page on called-in and recovered planning decisions covers the Secretary of State’s role in exceptional cases.
Which NPPF applied to the June 2026 decision?
The timing needs care because national Green Belt policy has changed since this appeal was decided. The Inspector’s report and Secretary of State’s letter expressly identify the applicable Framework as the December 2024 NPPF, updated on 7 February 2025.
The decision was made on 29 June 2026. It should therefore not be analysed retrospectively by applying the later August 2026 NPPF as though that were the policy framework used by the Inspector and Secretary of State.
Planning Geek’s NPPF timeline and 2024 versus 2026 NPPF comparison help keep those versions separate.
What the Chalfont St Peter Green Belt challenge has yet to decide
For now, the Secretary of State’s planning permission remains the decision under challenge. Buckinghamshire Council and SENSE4CSP allege that the decision-making process was legally flawed; the Secretary of State decided that the identified harms were clearly outweighed and that very special circumstances existed; and the High Court has yet to determine whether the legal challenge succeeds.
That three-way distinction is important. A challenge being filed is not a finding of unlawfulness, just as the existence of a Green Belt designation did not prevent the Secretary of State from finding very special circumstances on the evidence before him.
Published: 26th August 2026 — Chalfont St Peter Green Belt challenge
