Conservation · Planning
Demolition in a Conservation Area: When You Need Permission
Demolishing a building — or a substantial part of one — in a conservation area usually needs planning permission, and doing it without is a criminal offence. This guide explains "relevant demolition", the thresholds, and the position outside conservation areas.
The short answer
In a conservation area, demolishing an unlisted building — or a substantial part of one — usually needs planning permission. This is called "relevant demolition", and carrying it out without the necessary permission is a criminal offence under the planning acts. Because so much of prime London is designated, a "demolish and rebuild", or removing a rear return or an outbuilding, frequently needs permission that owners do not expect.
What counts as relevant demolition
The control catches the substantial demolition of a building in a conservation area — broadly, buildings of 115 cubic metres or more, and gates, walls, fences or railings over a certain height. The demolition of the whole or a substantial part of a dwellinghouse in a conservation area can require permission, with the council weighing the contribution the existing building makes to the area against the merits of what would replace it. Minor works and very small structures can fall outside it, but the threshold is lower than people assume.
Outside a conservation area, and for listed buildings
Outside a conservation area, demolition of a building is often permitted development, but you must first apply to the council for prior approval of the method of demolition and the restoration of the site before starting. A listed building is stricter again: demolishing a listed building, in whole or in part, needs listed building consent, and unauthorised demolition of a listed building is a serious criminal offence.
Why it matters for a rebuild
The practical trap is a project that treats demolition as separate from the new design. In a conservation area the demolition and the replacement are judged together — the council will not readily permit the loss of a building that contributes to the area unless what replaces it is at least as good. Establishing early whether demolition needs permission, and designing the replacement to justify it, is what keeps a rebuild on track. We assess the conservation-area position at feasibility and prepare the case accordingly.
Frequently asked questions
Do I need permission to demolish a building in a conservation area?
What is "relevant demolition"?
Do I need permission to demolish a garden wall in a conservation area?
What about demolition outside a conservation area?
What if the building is listed?
Is unauthorised demolition really a criminal offence?
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