Phelps v First Secretary of State London Borough of Bromley & Ors

An appeal against an enforcement notice decision on a point of law will succeed for a material error of fact only where the alleged mistake concerns an existing fact or the availability of evidence, the fact is established as uncontentious and objectively verifiable, the appellant was not responsible for the mistake, and the mistake materially affected the decision. Where the measurement relied on is contentious, or the appellant contributed to it, the criteria are not met. An inspector may include the volume of construction materials in calculating permitted-development cubic-capacity limits, while excluding unenclosed space.

The appellant challenged an inspector’s dismissal of his appeal against an enforcement notice concerning a rear extension and roof balcony. The notice required removal of the balcony railings and cessation of the balcony use. The appeal to the High Court was confined to whether there had been a breach of planning control under the permitted-development provisions of the Town and Country Planning (General Permitted Development) Order 1995.

The appellant alleged that the inspector had double-counted enclosed space and made material errors concerning the extension’s dimensions and the surface from which its height should be measured. The central issue was whether those matters amounted to errors of law through material errors of fact.

1. Appeal dismissed. The inspector’s decision that the extension exceeded the permitted-development cubic-capacity limit was upheld.

2. The court accepted the approach in E and R v SSHD [2004] EWCA Civ 49. A mistake of fact may constitute a separate ground of challenge on an appeal on a point of law where: there is a mistake as to an existing fact or the availability of evidence; the fact or evidence is established, meaning uncontentious and objectively verifiable; the appellant or advisers were not responsible for the mistake; and the mistake materially affected the reasoning.

3. The inspector had not impermissibly counted the volume of space enclosed by the parapet and railings. His decision treated the volume of the parapet and railings themselves as relevant, but did not include the unenclosed space within them. That was a permissible approach to calculating cubic capacity.

4. The alleged error in using a height of 2.9 metres was not established as an uncontentious factual mistake. The material before the inspector supported that measurement, and the appellant was no less responsible than the local authority for the measurements relied upon.

5. The dispute over whether the height should be measured to the roof covering or to the decking was likewise contentious. The appellant therefore failed to satisfy the requirements for a material error of fact amounting to an error of law.

6. The inspector’s conclusion that the extension was not permitted development under Class A was consequently lawful, and the appeal was dismissed.

• High Court (Administrative Court): appeal under section 289 of the Town and Country Planning Act 1990 dismissed. The inspector’s enforcement notice appeal decision dated 20 January 2006 was upheld.