You can, but in Camberwell it is a negotiation before it is a building project. Hundreds of listed buildings sit in and around the area. Conservation areas cover a large share of the streets. The ground under all of it moves with the weather. Neighbours keep applying anyway, and the planning office has seen every version of the idea.
Historic England lists 394 buildings in and around Camberwell. Two are Grade I, five are Grade II* and the other 387 are Grade II. Listing covers the inside as well as the outside, so on a listed house even a replaced staircase or a knocked-through wall needs listed building consent on top of any planning permission. The two Grade I buildings make the headlines. The 387 at Grade II are the ones a buyer is likely to end up living in.
The box drawn around Camberwell takes in 31 conservation areas, including Camberwell Grove, Camberwell Green, Addington Square and Cobourg Road. Inside a conservation area the council takes an interest in roofs, front elevations, windows and demolition that it would leave alone elsewhere. On Camberwell Grove the roofline effectively belongs to everyone who walks up it.
None of this stops people trying. Between April 2024 and June 2026 the council logged 1,155 planning applications in the area, 523 of them in the last twelve months. Camberwell alters its homes constantly. A rear extension proposed here will have a dozen cousins in the council's files, and the planning officer will know every one of them.
The ground needs a structural engineer, and there is no cause for panic. The British Geological Survey puts Camberwell's shrink-swell hazard at class 3, and every postcode in the area reaches that class. Shrink-swell ground expands when wet and shrinks when dry, so a new extension usually needs deeper foundations than a builder quoting by the square metre might assume. Trees near the back wall get a say in the design as well.
Five listed buildings in the area are on Historic England's Heritage at Risk register. Those are buildings in poor condition, and any repair will draw close scrutiny and may attract grant support. For someone buying an ordinary flat or terrace nearby, they are scaffolding to walk past, and they make no difference to the risk on your own house.
In practice, the permitted development rights that let some homeowners build small extensions without a full application are narrower in conservation areas, and they never replace listed building consent. With about four in five Camberwell homes being flats, many buyers will be applying for planning permission for changes a detached-house owner elsewhere would simply build. The council's planning register will show whether a property is listed, which conservation area it sits in and what the previous owners already applied for, and that is the one search worth doing before getting attached to a loft plan.
Freedom to extend or alter is poor in Camberwell. The work is possible, and it arrives slowly, with the conservation officer's name on it.