Conservation area status doesn't remove all permitted development rights, but it tightens several of them, especially for side extensions and roof work.
In conservation areas, cladding the exterior in stone, artificial stone, pebble-dash, render, timber, plastic or tiles is not permitted development.
Side extensions in conservation areas commonly lose permitted development rights entirely and need full planning permission.
Roof extensions and dormers facing a highway are more likely to require full planning in a conservation area.
Outbuildings behind the principal elevation generally keep more of their PD rights, but curtilage and coverage limits still apply.
England only. Takes about a minute.
Last reviewed 2026-09-01. Guidance, not legal advice.