House Extensions Purley

GS Renovation plans and builds extensions across Purley, where interwar semis and detached houses sit on the kind of generous plots that suit rear and side-return additions. We take on the groundworks, the steelwork, the roof and the full fit-out as one continuous project.

In Purley, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Purley: the structural engineer we appoint designs the structure, we build it, and building control signs it off.

Rear and side extensions on Purley plots

The wide, deep gardens common to Purley's older houses give real scope for single and double storey rear extensions, side infills along the gap between semis, and wrap-around designs that combine the two. We start with the foundations and groundworks, dig to the depth the ground conditions require, and build up in blockwork before setting the steel beams that carry the new openings into the existing house.

Because these interwar homes were built with modest kitchens at the back, the most popular Purley project opens the rear into a large kitchen-diner with the garden brought into view. We match the new brickwork and roofline to the original as closely as the materials allow, so the extension reads as part of the house rather than an obvious bolt-on.

Housing in Purley

The Council Tax list puts Purley at about 8,800 homes, 50% flats against 49% houses; 32% went up before 1919, 24% between the wars and 42% after 1945. Since many homes here are flats, a flat in Purley has no householder permitted development rights, so extending one needs planning permission and the freeholder's consent.

Extending a house on the Webb Estate or in Upper Woodcote Village

Croydon's appraisal describes the Webb Estate and Upper Woodcote Village as residential conservation areas in Purley, and the rules there change what can be built. The appraisal says garages and outbuildings should not protrude in front of the main building line, so a new garage goes beside or behind the house, not forward of it. Croydon's conservation guidance SPD says front extensions to buildings in conservation areas are generally considered to be unacceptable, which makes the front of the house the least likely place to gain space.

Growth therefore goes to the side or rear, and even that is limited. The same SPD says two storey rear extensions are generally unlikely to be considered acceptable in conservation areas, and planning permission is required there for side extensions and some rear extensions. For a Purley family wanting more room, the realistic first design is single storey at the back. On cost, Croydon states that CIL is not charged on extensions or other home adaptations, so the levy is not a factor in that choice.

Planning and party walls in CR8

Many single storey rear extensions on Purley's larger plots fall within permitted development, but this depends on the individual property, its previous alterations and whether any planning constraints apply. Double storey work, anything to the front, and larger footprints usually need a full planning application to Croydon Council. We assess your house honestly and tell you which route applies before any work is priced or started.

Where an extension is built up to or across the boundary with a neighbouring semi, the Party Wall Act comes into play and you serve notice on the neighbour as building owner, using the drawings we supply. We coordinate the planning route and the building regulations approval together, so the paperwork moves in step with the build and you are never left waiting on a consent that should have been sorted earlier.

Kitchen extensions in Purley

69% of the houses in Purley are semi-detached or detached, which usually leaves room for a kitchen extension across the full rear width, with a steel beam over the opening into the house. The fit-out is priced on its own page, kitchen renovation in Purley; the build figures are in the table above.

Side return extensions in Purley

Side returns belong to the older terraces, and only 13% of homes in Purley are terraced houses, so they are the exception here; on a semi-detached or detached house a full-width rear extension or a side extension usually does the job. Our side return extension page covers the build in detail, with build rates of £2,400 to £3,200 per m².

Double storey extensions in Purley

Under permitted development a two-storey rear extension can go no more than 3 metres beyond the original rear wall and must stay at least 7 metres from the rear boundary, and in a conservation area it is not permitted development at all. Many gardens are too short for the 7 metre rule, so a double storey extension in Purley often needs planning permission from Croydon Council. With 34% of homes here semi-detached or detached, the side of the house is often an option too. Croydon's appraisal describes the Webb Estate and Upper Woodcote Village as residential conservation areas in Purley (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.

• Party wall process explained, and the extension built to the award
• Levels, drainage and landscaping made good around the new build
• Bi-fold, sliding and French door openings to the garden

VOA Council Tax stock of properties, March 2025, for Purley North and Purley Central. Counts rounded by the VOA.

Next steps that tend to follow house extensions in Purley: RSJ and steel beam installation in Purley, house extensions across Croydon, side return infills, party walls and extensions, house extensions anywhere in London and Side Return vs Rear Extension.

Why Purley Homeowners Choose GS Renovation

Homeowners in Purley come to GS Renovation because we manage an extension from the first trial hole to the final coat of paint with one accountable team. Our founder's 30+ years on the tools means we understand the interwar construction, the generous plots and the local planning picture. You get honest advice on permitted development, tidy site management and a build that lasts.

• Foundation depth set after trial holes, drains and trees are checked
• Free, no-obligation quotations
• Drainage diverted or built over with the right approval in place

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.