What is a conservation area, and what changes when your house is in one?
A conservation area is an area designated by the council for its special architectural or historic interest. Designation does not freeze it, but it removes some permitted development rights, adds control over demolition and trees, and raises the bar on design in any application.
Conservation area in one paragraph
A conservation area is an area designated by the council for its special architectural or historic interest. Designation does not freeze it, but it removes some permitted development rights, adds control over demolition and trees, and raises the bar on design in any application.
Legal basis: Section 69 of the Planning (Listed Buildings and Conservation Areas) Act 1990, with the duty to pay special attention to character and appearance at section 72.
What the London numbers show
These are government figures for all 33 London boroughs, not estimates. They are the same numbers we publish on each borough page, summed — so if a borough page and this page ever disagreed, one of them would be wrong.
Householder decisions across the 33 London boroughs
Every householder application decided by a London council, 2025 Q2 to 2026 Q1.
| Applications decided | 24,758 |
|---|---|
| Granted | 21,185 |
| Granted | 86% |
Source: Ministry of Housing, Communities and Local Government (PS2 district planning application statistics). Open Government Licence v3.0 Extracted 2026-08-16.
What designation actually changes
Three things change at once. Some permitted development rights fall away automatically: side extensions and roof extensions lose their permitted status, cladding is excluded, and outbuilding rights are tightened. Demolition of a building above a threshold size needs consent in its own right. And any tree work needs six weeks' written notice to the council, which gives it time to make a tree preservation order.
The fourth change is not a rule but a duty, and it is the one that decides applications: the council must pay special attention to preserving or enhancing the character and appearance of the area. In practice that turns design details into policy questions — window materials, the proportion of glazing, the visibility of a roof addition from the street.
What designation does not do
It does not list your building, it does not make the interior controlled, and it does not prevent extension. Rear extensions not visible from the street are frequently approved in conservation areas across London. What designation removes is the assumption that you can proceed without asking.
How do I know what the council will accept?
Read the conservation area appraisal and management plan. Nearly every London borough publishes one per area, and it names the specific features that give that area its character — the rhythm of the terrace, a particular brick bond, the survival of original sash windows, the front boundary treatment. An application that engages with the named features is a different proposition from one that ignores them, and the appraisal is public.
Rear-of-property work is generally where the flexibility sits. A mansard on a street of uninterrupted parapet roofs is a different conversation from a rear dormer on a street where half a dozen already exist.
Conservation area: common questions
Can I extend a house in a conservation area?+
Do I need special permission to replace my windows?+
Is a conservation area the same as a listed building?+
Where conservation area affects the drawings
Sources
Not sure how conservation area applies to your property?
Send us the address and what you want to build. We will tell you which route applies before you spend anything on drawings.