You can extend a home in West Brompton, but expect to ask permission for nearly everything. The area has over two hundred listed buildings and three conservation areas in and around it. The ground moves with the weather. And most homes here are flats, where a whole building has a say before anyone builds.
There are 212 listed buildings in the area. One is Grade I, 25 are Grade II* and 186 are Grade II. Listing covers the inside of a building as well as its front, so on any of them, new windows, a moved wall or a changed staircase can need listed building consent as well as planning permission. Work done without consent is a criminal offence. Getting it after the fact is called enforcement.
Three conservation areas fall within the wider box around West Brompton. Inside one, the council controls changes to the look of a street more tightly, so demolition, some roof and front-elevation work, and work to trees can all need permission that would be automatic elsewhere. Beatrix Potter lived round here, and the planning department likes things kept as they were drawn just as much as she did.
The neighbours are doing it anyway. The council logged 803 planning applications in the area between April 2024 and June 2026, 249 of them in the last twelve months. People here do alter their homes. They just fill in a form first.
The British Geological Survey puts the whole area in class 3 for shrink-swell, a hazard class for clay ground that swells when wet and shrinks when dry. For an extension that means deeper foundations than a builder might quote by habit, and a structural engineer's view on the soil and on any trees close to the footings. It doesn't mean the houses are moving. It means the foundation design matters more here.
Two listed buildings in the area are on Historic England's Heritage at Risk register. A building on that register is in poor condition, may qualify for repair grants and will get close attention from the council and Historic England. For the owner of an ordinary flat down the road, the effect is mostly the scaffolding.
Permitted development, the rights that let householders build some extensions without applying, applies to houses. Flats don't get it. Listed buildings and conservation areas remove or narrow it further. In a neighbourhood made mostly of flats, the first permission to look for is in the lease. Read the alterations clause and find out whether the freeholder's consent is needed, because that answer can stop a project before the council ever sees it.
Your freedom to extend in West Brompton is limited. Some work does go ahead, but it gets there through consents, freeholders and engineers, and a lot of what's possible is decided by somebody else.