Warwick District Council v Secretary of State for Levelling Up, Housing and Communities & Ors

The interpretation of planning policy is a question of law for the court, while its application to particular facts remains a matter for the planning decision-maker. Exceptions to the Green Belt restriction on new buildings must be construed carefully, but not artificially or so narrowly as to exclude development falling within their proper meaning. Under paragraph 149(c) of the National Planning Policy Framework, an extension of a building is not necessarily required to be physically attached to it. Whether a detached structure is an extension depends on matters including proximity, purpose, use and relative size. Physical separation is not conclusive.

The claimant local authority refused planning permission for the replacement of a detached outbuilding at a dwelling in the Green Belt. The inspector allowed the developers’ appeal, treating the proposed garden room/home office as an extension within paragraph 149(c) of the National Planning Policy Framework, although it was physically detached from the dwelling.

With permission, the authority brought a statutory review under section 288 of the Town and Country Planning Act 1990. The central issues were whether the court should determine the meaning of “the extension … of a building” and whether paragraph 149(c) required physical attachment.

1. Claim dismissed. The inspector had not erred in law by treating a physically detached proposed outbuilding as capable of being an extension for paragraph 149(c) of the National Planning Policy Framework.
2. The meaning of planning policy is a question of law for the court. The court must distinguish interpretation from application. Interpretation identifies the legitimate meaning and boundaries of the policy; application to the facts involves planning judgment. The policy must be read in context, having regard to its subject matter, the wider policy framework and the planning objectives it serves.
3. Paragraph 149(c) is not confined to physically attached structures. The word “extension” can refer to a process of enlargement, and paragraph 149 concerns new buildings more generally. A detached structure may be an extension of another building where the relationship between them supports that conclusion.
4. The relevant assessment remains fact-sensitive. Relevant considerations include proximity, purpose and use, and the size and relationship of the buildings. Physical connection is not conclusive. The interpretation does not remove the requirement that additions must not be disproportionate over and above the size of the original building.
5. The exceptions in paragraph 149 are to be construed narrowly in the sense that they should not be extended by inference or artificial reasoning to development outside their language. They should not be construed artificially restrictively where development properly falls within an exception. The policy must be read in the context of the importance and purposes of the Green Belt.
6. Sevenoaks concerned different policy wording and the extension of dwellings rather than buildings. It therefore provided only limited assistance and was distinguishable, although the earlier approach to detached domestic adjuncts was relevant to the contextual interpretation of the current policy.

First-instance statutory review under section 288 of the Town and Country Planning Act 1990. Permission to reconstitute the claim from judicial review to statutory review was granted by Lang J. The claim was dismissed by Mr Justice Eyre.