London Conservation Area Checker
Pick a borough, type a postcode, and see whether it falls inside a conservation area or an Article 4 direction. The boundaries are the ones on the national planning register, and the check runs in your own browser — nothing you type is sent anywhere.
What changes when a property is in a conservation area?
Designation does not freeze a building, and it does not stop an extension. What it does is remove the shortcuts. Most of the permitted development rights that let a house be altered without an application fall away, side extensions and roof additions among them, and demolition needs consent in its own right. A rear extension is usually still achievable; it needs a planning application and a heritage statement rather than a lawful development certificate, and the council will expect materials, window details and proportions to answer to what is already there.
The practical consequence is a longer route to the same result, and a design that has to be argued for rather than asserted. That argument is won on drawings, which is where a chartered practice earns its fee: the officer is reading elevations, not intentions.
What does an Article 4 direction take away?
An Article 4 direction withdraws a permitted development right that would otherwise apply. It is made by the council for a defined area, it names the classes it removes, and inside that area the work it covers needs a planning application that the council is free to refuse. Directions are often laid over a conservation area but they are a separate instrument, and a property can sit inside one and not the other.
This is the designation that catches owners out, because nothing about the street announces it. The checker names the direction covering a postcode and lists the classes it removes, which is the information that decides whether you are applying or certifying.
How much of London is designated?
| On the register | Across the 33 boroughs |
|---|---|
| Conservation areas | 1,138 filed by the 33 borough authorities |
| Land they cover | 26,137 hectares |
| Article 4 areas | 2,300 |
| Boroughs publishing Article 4 boundaries | 17 of 33 |
| Postcode units indexed for the check | 180,837 |
| Most conservation areas | Richmond upon Thames, 85 |
| Most Article 4 areas | Waltham Forest, 807 |
What this checker cannot tell you
Three limits, all of them worth knowing before you rely on an answer. The boundaries are simplified to roughly twelve metres so they draw quickly, so a property sitting on a line cannot be settled here; a postcode within thirty metres of an edge is reported as unresolved rather than guessed at. A postcode covers a run of houses rather than one address, and a conservation boundary can run down a garden line instead of a road. And an empty Article 4 layer is not evidence: sixteen of the 33 boroughs have filed nothing at all to that dataset, and not one of them is thereby without directions.
Where the answer matters to a decision you are about to make, send us the address. Checking it against the council’s own map costs us a few minutes and costs you nothing.
Conservation areas and Article 4 directions from the planning.data.gov.uk registers, retrieved 15 August 2026 and re-checked 1 September 2026. Postcode positions from OS Code-Point Open, retrieved 16 August 2026. Contains public sector information licensed under the Open Government Licence v3.0. Hectares are computed from the published boundaries.