London Borough of Hounslow v Secretary of State for Communities and Local Government (The Planning Inspectorate) & Anor

A previous planning appeal decision that is materially indistinguishable from the case before an inspector is a material consideration. The inspector must consider it and give reasons if departing from it. There is no general duty to undertake extensive inquiries into decisions not drawn to the inspector’s attention. However, where an appeal notice identifies a previous appeal concerning the same development, the Inspectorate may be required to make a simple check. A mistake of fact causing unfairness may amount to an error of law where the fact is established and objectively verifiable, the mistake materially affects the decision, and responsibility for the error is appropriately assessed. In a planning appeal, the public interest in reaching the correct decision may justify quashing the decision despite fault by another participant.

The claimant challenged an inspector’s decision allowing an enforcement appeal concerning the use of a garden outbuilding as a separate dwelling and directing that the enforcement notice be quashed. The challenge comprised an appeal under section 289 and a claim under section 288 of the Town and Country Planning Act 1990.

A previous inspector had refused retrospective planning permission for the same bungalow. The local authority failed to disclose that decision accurately, although the enforcement appeal notice referred to the earlier planning appeal. The second inspector was therefore unaware of the earlier decision and reached the opposite conclusion. The central issue was whether that failure amounted to an error of law justifying quashing the decision.

1. Outcome. The section 289 appeal and section 288 claim were allowed. The inspector’s decision was quashed and the matter was remitted to the Secretary of State for a fresh decision.
2. A previous appeal decision materially indistinguishable from the case before an inspector is capable of being a material consideration. Consistency is important, although an inspector must exercise independent judgment. If the inspector departs from the earlier decision, reasons must be given for doing so. This applied the principle in North Wiltshire District Council v Secretary of State for the Environment (1992) 65 P&CR 137.
3. The Court of Appeal’s reasoning in E and R v Secretary of State for the Home Department [2004] QB 1044 supported recognition of mistake of fact causing unfairness as a separate ground of challenge. The relevant considerations included an existing fact or evidence, its being established by uncontentious and objectively verifiable material, the claimant’s lack of responsibility for the mistake, and the mistake’s material contribution to the reasoning.
4. There is no general obligation on an inspector to conduct extensive research or make inquiries about every potentially relevant decision. The principle in Granchester Retail Parks Plc v Secretary of State for Transport, Local Government and the Regions [2003] EWHC 92 (Admin) remained generally correct. The present case was different because the appeal notice identified an earlier planning appeal relating to the relevant refusal. A simple check would have disclosed a directly relevant decision. The Inspectorate therefore bore some responsibility for the failure, alongside the local authority.
5. The mistake was material. The later inspector could lawfully prefer his own assessment, but only after considering the earlier decision and giving reasons for preferring it. The claimant’s errors did not cancel the Inspectorate’s fault, particularly given the public impact of the planning decision. The decision could not stand.
6. The claimant was awarded £3,500 inclusive of VAT and all costs considered by the court. Permission to appeal was refused.

• Planning Inspectorate: On 11 October 2007 an inspector allowed the enforcement appeal, granted planning permission and directed that the enforcement notice be quashed.
• High Court (Administrative Court): The section 289 appeal and section 288 claim were allowed. The inspector’s decision was quashed and remitted for a fresh decision.