Aaron Scott Canham, R (on the application of) v Calderdale Metropolitan Borough Council

When applying the four-year enforcement time limit, a planning authority must identify the relevant building operation and decide, as matters of fact and evaluation, when it was substantially completed. Later works do not reopen immunity where they are separate, non-integral additions to an already usable structure. A structure is a caravan if it satisfies the statutory habitation and mobility requirements; movement need not be possible without incidental removal steps. A decision whether to issue an enforcement notice is not adjudicative, so apparent-bias principles do not apply, although ordinary public-law requirements remain applicable. In any event, properly reasoned reconsideration by the same officers, following new matters and evidence, did not create a real possibility of bias.

The claimant sought judicial review of the Council’s refusal to take enforcement action concerning raised concrete plinths and a park home beside a listed former farmhouse. The Council concluded that the plinths had been substantially completed more than four years earlier, that the park home was a caravan capable of being moved by road, and that enforcement concerning later additions was not expedient.

After successive reconsiderations, the claimant challenged the application of the enforcement time limit, the caravan classification, the decision not to enforce against the 2025 works, and the involvement of the same officers in successive decisions. The hearing proceeded as a rolled-up application to re-amend the claim and determination of its merits.

Outcome. Permission to re-amend the statement of facts and grounds was granted, but all grounds of challenge failed and the application for judicial review was refused.

1. Under section 171B(1) of the Town and Country Planning Act 1990, the authority had to identify the relevant building operation and decide when it was substantially complete. Those were matters of fact and evaluation. The Council was entitled to treat construction of the plinths, rather than the whole process of making the site suitable for occupation, as the relevant operation. The plinths were usable and functional in 2021. The later brick skirt, patio, railings, steps and drainage works were separate, non-integral improvements following the park home’s installation and did not reopen immunity.
2. The statutory caravan definitions required a structure designed or adapted for human habitation and capable of being moved from one place to another. For a twin-unit structure, physical capability of movement by road was required, disregarding whether movement would be lawful under highway legislation. The Council had sufficient evidence that the park home could be jacked up and removed. The need to take incidental steps, including possible disconnection of a downpipe or removal of part of the brick skirt, did not itself create the permanence and attachment of a building.
3. Under section 172(1) of the Town and Country Planning Act 1990, expediency was for the Council to assess having regard to the development plan and other material considerations. The Council was not required to consider the speculative possibility that enforcement would cause the site owner to remove the park home. It had considered the 2025 works in the round and was entitled to conclude that enforcement would not deliver a meaningful planning outcome.
4. Part 2, Class A of the Town and Country Planning (General Permitted Development) (England) Order 2015 could apply to the brick skirt because it enclosed the perimeter of the plinth, notwithstanding its largely aesthetic purpose. The Council had nevertheless considered whether removal of all the 2025 works should be required.
5. The common-law principles of apparent bias apply to adjudicative decisions. A decision under section 172(1) was an assessment by the planning authority, not an adjudication. Other public-law requirements, including the prohibition on actual bias and the duties to consider relevant matters and act rationally, remained applicable. Even assuming apparent-bias principles applied, a fair-minded and informed observer would regard the successive reconsiderations as genuine, particularly in light of the new issues and fully reasoned reports. The circumstances were distinguishable from R(Carlton-Conway) v London Borough of Harrow [2002] EWCA Civ 927.

• High Court: DHCJ Ockleton refused permission to apply for judicial review on 15 August 2025. On 10 November 2025, Holgate LJ granted permission on the remaining issue, remitted the claim to the Planning Court, and refused permission on the proposed grounds based on the Planning (Listed Buildings and Conservation Areas) Act 1990.
• High Court (Planning Court): Permission to re-amend was granted, but the substantive claim was dismissed by refusal of the application for judicial review.