Builders in Orpington

The long rear gardens on Orpington's inter-war semis are the reason extensions dominate the local building market. Where an inner-London terrace is constrained to a side-return, a Crofton or Poverest semi can usually take a full-width single-storey rear extension without swallowing the garden. Across South London these run £30,000–£50,000, and Orpington tends to sit toward the lower half because access for materials and skips is easier than on a terraced street.

Most of Orpington retains full permitted development rights, so many rear extensions proceed without a planning application. That is not the same as needing no approvals: Building Regulations still apply, and a Building Control application is required regardless of whether planning is. If the extension goes up to or near a boundary shared with a neighbour, the Party Wall etc. Act 1996 is likely to be engaged and notice has to be served.

Loft conversions are the other common project. The 1930s roof profile in BR6 usually suits a rear dormer, which creates full head height where a simple rooflight conversion would not. Loft conversions run £40,000–£65,000 across South London. The head height under the existing ridge is the thing to measure first. If it is marginal, the conversion type and the price both change.

Garage conversions are cheaper and increasingly popular where the original garage is too narrow for a modern car. At £12,000–£22,000 they turn dead storage into a room, though the floor usually needs raising and insulating and the up-and-over door replacing with a wall and window.

When comparing builders in Orpington, ask who is handling the Building Control application and the party wall notices, and get it in writing. Those two items are where responsibility most often turns out to be assumed rather than agreed.

Listing data is refreshed continuously; pricing guidance was last reviewed in August 2026.