Yes, you can usually extend a house in Anerley, but more rules apply here than in most suburbs. Eight conservation areas reach into or near it. There are 18 listed buildings. Every part of it sits on clay that moves. Most homes are flats, so most of what people call extending here needs consent from someone else first, whether that is the council or the people who share the building.
The area takes in 18 listed buildings: one at Grade I, one at Grade II* and 16 at Grade II. Listing covers the inside of a building as well as the outside, and any work that affects its character needs listed building consent from Bromley council on top of normal planning permission. Most of those 18 are churches and public buildings, not ordinary houses, so for most buyers listing applies to the building next door, not their own.
The eight conservation areas in and around Anerley count for more. They include Belvedere Road, Anerley, Penge High Street, Crystal Palace Park and Alexandra Cottages on Parish Lane. Inside a conservation area, the council expects changes to respect the character of the street, which usually means closer scrutiny of anything visible from the road, of demolition and of trees. The same side extension can be straightforward on one street and a long correspondence about window frames two roads away. Bromley publishes its conservation area boundaries, and a property's planning history together with that map will show which side of the line a house is on.
Plenty of people alter their homes here anyway. Planning records show 376 applications across Anerley between April 2024 and June 2026, 173 of them in the last twelve months. That is proof people do apply here, and it says nothing about what is approved or how long decisions take.
The ground needs as much attention as the planning. The British Geological Survey rates the clay under Anerley at shrink-swell class 3, and every part of the area reaches that class. Clay of this kind swells when it is wet and shrinks when it dries, so extensions usually need deeper foundations, and a structural engineer should assess the ground near large trees before anyone digs. Building control will expect the foundations to be designed for it, and the cost goes into the budget from the start.
Four listed buildings in the area are on Historic England's Heritage at Risk register. That means they are in poor condition and their repair is being watched, and it can bring grant support for the owners. It puts no extra limits on the ordinary house next door. For one of the four, a buyer is taking on a repair project with closer oversight than an extension would get.
How much you can do without planning permission depends on what you own. A house outside a conservation area normally has permitted development rights for modest rear extensions and loft work. Inside a conservation area, those rights are narrower. A flat has no such rights for the building, and the freeholder and neighbours have a say alongside the council. Since two-thirds of Anerley's homes are flats, the most common extension project here is an argument with the lease. "Scope to extend" on the particulars for a flat in a converted house usually means a loft that belongs to someone else.
Your freedom to extend in Anerley is below average. Houses outside the conservation areas have room to grow on foundations designed for clay, while flats and homes on the protected streets face consent at every stage.