Single and double storey extensions in Merton. Trusted, professional, 30+ years' hands-on experience.
GS Renovation designs and builds extensions throughout Merton, working with the bay-fronted Victorian and Edwardian terraces and larger suburban homes near Wimbledon Common and Morden Hall Park. Across SW19, SW20, CR4 and SM4 we have over 30 years of experience turning tight rear yards and unused side returns into bright, well-built living space.

The side return alongside the rear closet wing is the classic opportunity on a Merton terrace. Infilling that narrow strip and pushing the back wall out creates the open-plan kitchen-diner that suits family life near Wimbledon and Mitcham. We handle the groundworks and foundations, the steel beams that carry the original rear wall, the roof with its rooflights, and the full fit-out inside.
Wrap-around extensions combine the side return with a rear addition for a larger footprint, while double-storey options add a bedroom above. On the generous plots found around Morden and the leafier SW20 streets there is often room to extend more ambitiously, always built to sit correctly against the existing solid-wall structure.
Whether your extension is permitted development or needs a full planning application depends on the property. Many single-storey rear extensions fall under permitted development, but larger schemes, side extensions, corner plots and anything near a conservation area may require permission from Merton Council. We assess your specific house first and prepare the right application rather than assume.
Every extension also brings building regulations for the foundations, steel and drainage, inspected as the work proceeds. Where your new footings or walls sit against the shared party wall, the Party Wall Act applies too, so you serve the notices your neighbours are entitled to and keep the whole approvals process moving in one coordinated programme.
Merton families choose GS Renovation because we manage the extension end to end, from the first structural drawings and the Merton Council application through to the finished kitchen. One accountable team means tidy working in an occupied home, honest pricing and a build that respects the period fabric, backed by 30+ years across the borough.
Really great job done in our bathroom to replace the shower head in the bathtub, and install a shower screen and caddy. We are very happy with the…
George was very friendly and helpful from start to finish. He worked really hard to ensure our kitchen was installed to a high standard and was…
We loved working with George and Ibrahim and would highly recommend them. They have done splendid job on our new kitchen refurb which including new…
FAQ
No. House extensions are priced from scope, so a Merton home is not quoted higher than the same house over in Wandsworth. Where costs do rise is in period stock and awkward access, both of which are checked at the SW19 property. GS Renovation shows those as separate lines so you can see the reason. The SW19 survey costs nothing and there is no obligation afterwards, in Merton or anywhere in Merton. 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.
Faster than most people assume, provided the survey is done early. The lead time on house extensions at an SW19 property is usually approvals and materials rather than labour, so GS Renovation starts both as soon as the Merton scope is signed off. Seasonal demand across Merton does move it. Email info@gsrenovationltd.co.uk for the current position on Victorian and Edwardian terraced properties. The SW19 survey is free and there is no obligation afterwards in Merton.
Happily. Previous Merton clients are usually willing to talk about how a house extensions project actually ran, including what went wrong and how GS Renovation dealt with it. We will point you at recent work near SW19 and in Wandsworth. The 31 MyBuilder reviews behind our 4.9 rating are public and cover the same ground. Ring 07472 424 226 to arrange a Merton introduction. Nothing about a Merton reference is curated by us at SW19.
It can. The Community Infrastructure Levy applies above 100 square metres of new floorspace, though a residential extension to your own home usually qualifies for relief if it is claimed before work starts. Missing that claim is expensive, so we flag it early on Merton projects.
It lengthens the preparation and the finishing. A house extensions job at an SW19 address of that age begins with investigation and ends with reinstating plaster, floors and joinery to match what is already in the Merton house. GS Renovation itemises both. Merton Council inspects the structural stages in between, exactly as it would in Merton generally. Email info@gsrenovationltd.co.uk and we will explain what house extensions adds in reinstatement at an SW19 address of that age.
It depends on the property. Many single-storey rear extensions on Merton terraces are permitted development within size limits, but side-return, double-storey and larger schemes, or homes in a conservation area, often need a full application to Merton Council. We check your exact address and permitted development rights first, then handle whichever route applies.
Regularly, though we do not pretend to cover everywhere. The house extensions patch runs across Merton and into neighbouring parts of South West London, which is wide enough to include most enquiries we receive from around SW19. GS Renovation would rather decline a job than take one it cannot service properly. Ring 07472 424 226 and ask about your Merton address. The answer comes the same day. The SW19 survey costs nothing and carries no obligation.
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 Merton. Explore what else we do locally:
Same Service, Nearby Areas
We carry out house extensions across Merton and the surrounding areas. Explore a nearby location:
Free, no-obligation quote for house extensions in Merton. Rated 4.9 from 31 reviews on MyBuilder, fully insured, and building control handled for you.