Exempted Development
Works that do not need planning permission if they stay within the limits and conditions in the planning regulations - rewritten on 27 July 2026 for the first time in a generation.
Schedule 2 of the Planning and Development Regulations lists classes of development that can proceed without planning permission - house extensions, garden buildings, minor works - each subject to conditions and limitations. On 27 July 2026 that Schedule got its biggest rewrite since 2001: S.I. 338 to 344 of 2026 raised the exempt rear-extension limit from 40 m² to 45 m², raised the garden-room limit from 25 m² to 30 m², and created new classes including the Class 3A habitable garden dwelling (32 to 45 m²), house subdivision into two units, and side and rear dormers. Exemptions can still be stripped case by case - protected structures, architectural conservation areas and prior planning conditions are the usual reasons - so the specifics always need checking.
More domestic work than ever now proceeds with no planning application, and most of it files no building-control paperwork either: planning-exempt works to houses need no fire safety certificate, so no commencement notice is required. That makes exempt jobs invisible to every public record until the work starts. The demand has not gone away - it now surfaces only where the homeowner raises a hand, which is why consented quote requests from tools like the exemption checker are the one reliable stream for this work.
Exempt works do not show up as planning applications, and mostly not in building control either: works that are exempt from planning and need no fire safety certificate need no commencement notice, and houses and domestic extensions need no fire safety certificate. The public traces an exempt project can leave are a Section 5 declaration on a council register, or, for a garden dwelling, the 14-day prior notification the council holds as an internal record.
Common questions
S.I. 338 to 344 of 2026 came into force: the exempt rear-extension limit rose from 40 m² to 45 m², garden rooms rose from 25 m² to 30 m², and brand-new exemptions arrived for habitable garden dwellings (Class 3A), house subdivision, dormers and front rooflights.
Not necessarily - every class carries conditions and limits, and exemptions can be removed for protected structures, in architectural conservation areas, or by a prior planning condition. A Section 5 declaration from the council settles a doubtful case.
The building regulations always apply to the work itself. But the paperwork mostly does not: works that are exempt from planning and need no fire safety certificate need no commencement notice, and houses and domestic extensions need no fire safety certificate - so most exempt jobs never appear in BCMS either.
Built for planning consultants & architects: Benchmark every authority, track every appeal, never miss a decision date.
This is a plain-English summary, not legal advice. Planning rules carry conditions and exceptions - always verify a specific case against the official source or a planning professional before acting.