Yes, you can extend a house in Ealing, but in a large part of the district you will need the council's agreement first. It has well over a hundred listed buildings. It has 17 conservation areas. The clay under the whole district moves with the weather. Neighbours file planning applications at a rate of about three a day, so getting permission is clearly possible, though rarely quick.
Ealing has 124 listed buildings: 3 at Grade I, 11 at Grade II* and 110 at Grade II. Listing covers the whole building, inside and out, so almost any alteration needs listed building consent from Ealing council on top of any planning permission. Replacing a window or removing an internal wall can count. Owning one of the 110 makes you the current keeper of a building the council expects to outlast you.
There are 17 conservation areas in and around the district, including Creffield, Brunswick, Grange and White Ledges and the Ealing Cricket Ground area. Inside them, the council controls demolition and alterations that change how a street looks, and work that would need no application elsewhere often does here. Living in Grange and White Ledges means planning a loft conversion around how the street looks from the pavement.
People clearly extend here. Ealing council logged 2,363 planning applications in the district between April 2024 and June 2026, 1,099 of them in the last twelve months. Those are submissions, and the counts say nothing about how many were approved. To see what is likely to get through on a particular road, search the council's planning register for the house and its immediate neighbours. A refused dormer two doors along will tell you more than any amount of general guidance.
The British Geological Survey puts all of Ealing's postcodes at class 3 for shrink-swell, a published hazard class for clay that swells when wet and shrinks when dry. For an extension, that usually means deeper foundations than a builder would dig on firmer ground, and a structural engineer's view on nearby trees and drainage before the design is fixed. It affects the cost of an extension more than whether you can build one, and the engineer's fee is better paid at the start than after a crack appears.
Historic England's Heritage at Risk register lists 14 listed buildings in and around Ealing. Those are buildings in poor repair, which can make them eligible for grant money and will certainly bring extra scrutiny of any work on them. For someone buying an ordinary semi down the road, they are someone else's problem.
Outside a conservation area and away from listed buildings, many modest rear and loft extensions to a house can go ahead under permitted development, the national rules that let some work proceed without a full planning application. Inside a conservation area those rights shrink, and on a listed building almost nothing counts as minor. Flats, which make up most of Ealing's homes, have no permitted development rights of this kind at all, so the freedom described here applies to houses.
A buyer who wants to extend has less freedom in Ealing than in most places, with the heritage controls covering a large part of the district and clay under all of it. Extending is still possible, but it involves more paperwork and more consultation than the typical buyer expects.