Single and double storey extensions in Coulsdon. Trusted, professional, 30+ years' hands-on experience.
GS Renovation designs and builds house extensions throughout Coulsdon, where the 1930s semi-detached and interwar houses tend to sit on generous plots with room to grow. Drawing on more than 30 years across Croydon and CR5, we handle everything from foundations to the final fit-out under one accountable team.

The wide plots common to Coulsdon's interwar houses suit rear extensions that stretch into the garden and side extensions that use the space beside the semi. A single storey rear extension typically opens the kitchen into a large kitchen-diner, which usually calls for a steel beam across the old rear wall, while a wrap-around design combines the rear and the side return into one broad living space.
We start with the groundworks, digging and pouring foundations to a depth agreed with building control for the ground conditions on your plot. Steel beams carry the openings, the roof is tied into the existing structure, and we complete the fit-out including plastering, electrics, plumbing, heating and decoration. You deal with one team from the first trench to the final coat of paint.
Whether your Coulsdon extension needs planning permission depends on the property. Many single storey rear extensions on these interwar plots fall under permitted development, which means no full application to Croydon Council, though double storey work, larger footprints and anything close to a boundary often does need a planning application. We assess your specific house and advise honestly which route applies before you commit.
Separate from planning, every extension must meet building regulations for its foundations, structure, insulation, drainage and fire safety, inspected as the work proceeds. Where the new build sits against the party wall shared with a neighbouring semi, the Party Wall etc. Act 1996 also applies, so we help you serve the necessary notices. We keep planning, building control and party wall matters running in step.
GS Renovation gives Coulsdon homeowners a single point of responsibility for the whole extension, from checking whether you need planning permission to pouring foundations, setting steel and finishing the interior. Thirty years of building across Croydon means we know the interwar stock, the generous plots and Croydon Council's requirements, so the project runs to plan.
George was brilliant. Lovely bloke, very reasonably priced and a perfectionist to boot. He completed our small kitchen renovation with care and great attention to detail. I've already recommended him to others.
Splendid job on our new kitchen refurb, including new flooring, moving the services, installing RSJ and preparing space for new back doors… George was always friendly, communicative and has an excellent attention to detail, ensuring everything is finished to a high standard.
Giorgio is an excellent and intelligent workman, and with very reasonable prices!… He paid a lot of attention to detail that is not common at all, and the final result was immaculate. Highly recommended!
FAQ
The cost of house extensions in Coulsdon depends on the size of the property, the specification and the scope of work. GS Renovation provides free, detailed and itemised quotations for every Coulsdon project. Call 07472 424 226 or email info@gsrenovationltd.co.uk for a no-obligation estimate. As a rough guide, house extensions in London typically starts from roughly £40,000 for a single-storey rear extension and rises with size and specification (indicative London ranges, MyBuilder and Checkatrade, 2026). Your figure depends on the size, specification and condition of the property, which is why we survey before quoting.
Most house extensions projects in Coulsdon take between two and eight weeks depending on the scope and whether structural work is involved. We provide a clear programme before work begins so you know exactly what to expect.
With more than three decades of hands-on trade experience behind us, GS Renovation is a trusted choice for house extensions in Coulsdon. You get one accountable team, transparent pricing, fully insured tradespeople and genuine aftercare on every project.
Many single-storey rear extensions in Coulsdon fall under permitted development, but side returns, double-storey extensions and work in conservation areas usually need full planning permission. We assess your property and manage both the planning application and building control.
Yes. A large share of Coulsdon's homes are 1930s and interwar properties, and we renovate them regularly. We plan each house extensions around their particular characteristics, such as cavity walls, regular original layouts and the generous plots that suit extending, so the result suits the building and meets building control.
It depends on the extension and the house. Many single storey rear extensions on Coulsdon's generous interwar plots are permitted development, needing no application to Croydon Council, but double storey extensions, larger footprints and boundary-hugging designs usually require full planning permission. We assess your property first and tell you clearly which applies, then handle the building regulations either way.
Yes. We work throughout Coulsdon and the CR5 area, as well as the surrounding parts of South London. Contact us on 07472 424 226 to confirm we cover your street.
Every Service, One Team
The same trusted team, 30+ years' hands-on experience and free, no-obligation quotes apply to every GS Renovation service in Coulsdon. Explore what else we do locally:
Steel beam installation, RSJ and structural alterations.
Safe load-bearing wall removal with steel beam support.
Structural alterations, new openings and steel support.
Chimney breast removal with gallows bracket or beam support.
Open-plan kitchen, diner and living conversions.
Full refurbishments and whole-house renovations.
Bespoke kitchen design and installation.
Luxury bathroom and wet-room refurbishment.
Same Service, Nearby Areas
We carry out house extensions across Coulsdon and the surrounding areas. Explore a nearby location:
Contact GS Renovation today for a free, no-obligation quote for house extensions in Coulsdon.
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