Single and double storey extensions in Eltham. Trusted, professional, 30+ years' hands-on experience.
GS Renovation designs and builds extensions across Eltham, where 1930s semi-detached and interwar houses sit on the generous plots that make expansion possible. With over 30 years of building experience in SE9 and the Royal Borough of Greenwich, we handle foundations, steelwork, roofing and the full fit-out as one accountable project.

The deeper gardens and wider side accesses common to Eltham's interwar houses lend themselves well to rear and side-return extensions. A single storey rear extension can turn a cramped kitchen into an open-plan kitchen-diner, while filling in the side passage widens the whole ground floor. We start with proper foundations and groundworks suited to the local soil, then bring in steel beams where the original external wall is opened up into the new space.
Double storey and wrap-around extensions add bedrooms and en-suites above the new ground floor, making the most of these family homes without moving out of the area. We manage the roof works, whether a pitched roof to match the existing house or a flat roof to a rear projection, and carry the project through to a finished, decorated interior with kitchen, bathroom and services all in place.
Whether your Eltham extension is permitted development or needs a full planning application depends on the property, its size and what has been built before. Many single storey rear extensions on interwar semis fall under permitted development, but larger projects, work to the front, or anything affecting the street scene may need permission from the Royal Borough of Greenwich. We advise honestly on which route applies to your SE9 home before any drawings are finalised.
Because Eltham semis usually share a party wall, extending near that boundary or building on a shared foundation brings the Party Wall Act into play, and notice must be served on your neighbour. Separately, the structural work itself, including the steel beams and new foundations, is controlled under building regulations and inspected by building control. We keep planning, party wall and building regs matters clearly separate and properly handled.
Eltham families choose GS Renovation because we build extensions that suit the interwar house, not a generic box. One team handles groundworks, steel, roofing and fit-out, advises whether you need planning or fall under permitted development, and manages party wall notices with neighbours. Backed by 30+ years in SE9 and across the Royal Borough of Greenwich, we deliver space you can actually use.
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 Eltham depends on the size of the property, the specification and the scope of work. GS Renovation provides free, detailed and itemised quotations for every Eltham 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.
A straightforward Eltham project can be done in a couple of weeks, while a larger house extensions with structural work runs longer. We set out a realistic, stage-by-stage programme before we begin so there are no surprises.
With more than three decades of hands-on trade experience behind us, GS Renovation is a trusted choice for house extensions in Eltham. You get one accountable team, transparent pricing, fully insured tradespeople and genuine aftercare on every project.
Many single-storey rear extensions in Eltham 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 Eltham'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 size and your specific house. Many modest single storey rear extensions on Eltham's interwar semis qualify as permitted development, but larger or two storey projects, or work facing the street, often need a planning application to the Royal Borough of Greenwich. We assess your SE9 property early and tell you clearly which route applies before committing to a design.
We do. GS Renovation covers all of Eltham and the SE9 area and the wider South East London. Call 07472 424 226 and we will confirm we work on your road.
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 Eltham. 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 Eltham and the surrounding areas. Explore a nearby location:
Contact GS Renovation today for a free, no-obligation quote for house extensions in Eltham.
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