Yes, you can extend most houses in Golders Green, but the planning rules above ground and the clay below it will both affect what you build. Hundreds of listed buildings stand in and around the area. Six conservation areas overlap it. Every part of it is on clay that shrinks and swells. The neighbours apply for planning permission all the time, which proves it can be done, and few of them would tell you it was quick.
There are 372 listed buildings in and around Golders Green: 2 at grade I, 29 at grade II* and 341 at grade II. Listing covers the whole building, inside and out, so almost any change that affects its character needs listed building consent from the council on top of planning permission. Grade II* and grade I buildings get the closest scrutiny of all. If the house you want is one of the 372, assume even an internal wall needs a conversation with the council first.
Six conservation areas fall within the area's bounds, including Golders Green Town Centre, Hampstead Garden Suburb and Hampstead Village (Heath Passage). In a conservation area the council has more control over demolition, trees and changes that can be seen from the street, and some work that needs no application elsewhere does need one here. Hampstead Garden Suburb demolished Temple Fortune Farm to build itself, and it has been far stricter about anyone else knocking things down ever since. Ask Barnet Council early whether the house falls inside a conservation area and whether any extra controls apply to it, because a boundary can run down the middle of a road.
People here alter their homes anyway, and in large numbers. Between April 2024 and June 2026 there were 2,011 planning applications in the area, and 839 of them came in the last twelve months alone. With that many applications, Barnet's planning officers have probably seen more of Golders Green's back gardens than the owners of the houses next door.
The ground matters as much as the paperwork. The British Geological Survey puts Golders Green in class 3 on its shrink-swell scale, its published measure of how much clay soil moves as it wets and dries, and the whole area reaches that class. For an extension, that means a structural engineer's view on how deep the foundations need to go, especially where there are trees nearby. The clay is manageable, but it makes digging the foundations cost more than many owners expect.
Ten listed buildings in and around the area are on Historic England's Heritage at Risk register. That register lists buildings whose condition is poor enough to worry the authorities. A building on it can attract grant money for repairs, and it will attract close attention to any work done on it. For the owner of an ordinary semi down the road, it is part of the local picture and no threat to their own plans.
The practical rule is that a house outside a conservation area and off the listed register keeps most of its permitted development rights, so many single-storey rear extensions and loft changes can go ahead without a full application. Inside a conservation area those rights are cut back, and listed buildings need consent for almost anything. Flats, which make up a large share of the homes here, never had the permitted development rights for extensions that a house has, so extending one starts with a full application.
Golders Green offers below-average freedom to change a home. An unlisted house outside the conservation areas can be extended with patience and a good engineer, and anything listed or in a conservation area should be bought on the assumption that it will stay largely as it is.