Single and double storey extensions in Southwark. Trusted, professional, 30+ years' hands-on experience.
GS Renovation designs and builds house extensions throughout Southwark, adding space to Victorian terraces in Peckham, Georgian townhouses in Dulwich and family homes across Camberwell. With over 30 years of experience in SE5, SE15, SE21 and SE22, we handle groundworks, steel, roofing and a full fit-out, and we guide you through permitted development and Southwark Council planning.

The most common Southwark extension fills in the side return of a Victorian terrace, widening a narrow rear kitchen into a full-width, open-plan space. This nearly always needs a steel beam where the original rear wall comes down, sized by a structural engineer and signed off by building control. We dig and pour new foundations to the correct depth, allowing for nearby trees on plots close to Peckham Rye, and tie the new structure into the existing brickwork.
Whether your extension is permitted development or needs a full planning application depends on the property. A modest single storey rear extension on a Peckham or Bermondsey house may fall under permitted development, but if you are in one of Southwark's conservation areas, or the home is listed, as many Dulwich and Camberwell properties are, you will usually need planning permission from Southwark Council. We assess this early and prepare the drawings and applications for you.
Where the plot allows, we build double storey and wrap-around extensions that add a bigger kitchen below and an extra bedroom or bathroom above. These are common on the larger Georgian and Edwardian homes around Dulwich Park and the leafier streets of SE21 and SE22. They need deeper foundations, more substantial steelwork and careful integration of the new roof with the old. Almost all double storey extensions in Southwark require planning permission rather than permitted development.
Because Southwark plots sit close together, extensions frequently trigger the Party Wall Act where you build up to or astride a boundary, or excavate near a neighbour's foundations. We serve the notices and keep neighbours informed. Once the shell is watertight, the same team completes the fit-out: plastering, electrics, plumbing, flooring, heating and decoration, so you deal with one contractor from the first trench to the final coat of paint.
Homeowners in Southwark choose GS Renovation because we run the whole extension in-house, from foundations and steel to roofing and finishes, across SE1 to SE22. We know the borough's period stock, its tight terraced plots and its conservation constraints, and we handle the Southwark Council applications and party wall notices so your project stays on track and fully compliant.
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
We price each Southwark project individually, because the cost of house extensions depends on far more than floor area. After a free survey you receive a clear written breakdown with no hidden extras. Call 07472 424 226 or email info@gsrenovationltd.co.uk. 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 Southwark 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.
GS Renovation knows Southwark's homes and how to renovate them properly. We handle the structure, the services and the finishes, deal with building control for you, and leave you with work that is certified, guaranteed and built to last.
Many single-storey rear extensions in Southwark 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 Southwark's homes are period, Georgian and listed properties, and we renovate them regularly. We plan each house extensions around their particular characteristics, such as conservation and listed-building rules, solid walls and original period features, so the result suits the building and meets building control.
It depends on your property. A small single storey rear extension can sometimes be permitted development, but much of Dulwich falls within conservation areas and includes listed buildings, where permitted development rights are restricted and planning permission from Southwark Council is normally required. We check your address and constraints at the outset, then prepare and submit the drawings and application on your behalf.
Absolutely. Our team works right across Southwark and the SE1 area and neighbouring parts of South London. Get in touch on 07472 424 226 to check coverage for your address.
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 Southwark. 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 Southwark and the surrounding areas. Explore a nearby location:
Contact GS Renovation today for a free, no-obligation quote for house extensions in Southwark.
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