Single and double storey extensions in New Malden. Trusted, professional, 30+ years' hands-on experience.
GS Renovation designs and builds extensions across New Malden, where interwar semis in KT3 sit on the generous plots that make rear and side-return additions so worthwhile. Drawing on 30+ years in Kingston upon Thames, we handle the groundworks, steelwork, roof and full fit-out, turning tired 1930s layouts into bright, open family space.

The classic New Malden extension pushes into the back garden or fills the narrow side passage of a 1930s semi to create a large kitchen-diner across the rear. Because the original back wall is load-bearing, we install steel beams sized by a structural engineer, then pour proper foundations and manage the groundworks first, checking for the mature garden trees common on these generous interwar plots before we dig.
Some New Malden extensions fall under permitted development, while others need a full planning application to Kingston Council, and it depends on the size, height and position of your property, whether it has been extended before, and any local restrictions. We assess your specific KT3 home, advise honestly which route applies, and prepare the drawings and paperwork accordingly.
The wide plots typical of New Malden's interwar streets often suit a wrap-around that combines a rear and side extension, or a double storey addition that adds a bedroom and en-suite over a bigger ground floor. These larger projects almost always need planning permission from Kingston Council rather than relying on permitted development, and we manage that application alongside the structural design.
Where the new build sits against the shared boundary of a semi, the Party Wall Act comes into play, so you serve notices on the adjoining owner before excavation begins. From foundations and steel frame through roofing, glazing and the full internal fit-out of plastering, wiring, plumbing and decoration, one GS Renovation team sees the whole KT3 extension through to completion.
Homeowners in New Malden choose GS Renovation because we manage the extension from first drawing to final coat. We tell you plainly whether your KT3 project is permitted development or needs a planning application, handle the party wall notices your semi requires, and build the structure and fit-out with one accountable team. Over 30 years in Kingston upon Thames stands behind the work.
George was a great find. The job required re-plastering the walls before fitting acrylic panels. He also re-plumbed the shower waste under the solid…
I am very happy to recommend George after he completed the work on my 2 bathrooms. He worked very hard to make sure everything was completed and even…
My husband and I are extremely pleased with the work. The standard of the work is outstanding and Saiid has a great eye for detail and will not leave…
FAQ
Not by much, and not because of the postcode. What raises a house extensions figure here is the housing rather than the location: 1930s semi-detached and interwar suburban houses on generous plots take more making good than a modern estate. Access and parking around KT3 affect the labour line too. GS Renovation prices the property in front of it rather than applying a New Malden or South West London multiplier. Ring 07472 424 226 and GS Renovation will explain what actually moves the figure at KT3. 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.
Usually yes, depending on which rooms are affected. For most house extensions projects at a KT3 address we seal the work area, protect the routes through, and agree hours so a New Malden household can carry on. Where services are off for a period, GS Renovation tells you which days in advance. Full refurbishments are the exception, and we say so honestly. GS Renovation seals the KT3 work area and agrees hours before house extensions begins in New Malden.
We build to a design, we do not write one. Where house extensions in a KT3 home involves beams, openings or altered load paths, GS Renovation appoints an independent structural engineer and coordinates them through Kingston Council sign-off. That separation protects the New Malden homeowner. Propping and sequencing on site are then ours to get right. Ring 07472 424 226 and we will explain the Kingston upon Thames sequence. The engineer is appointed and paid through the Kingston upon Thames contract.
Many single-storey rear extensions in New Malden fall under permitted development, but side returns, double-storey extensions and work in conservation areas usually need full permission. We assess your KT3 property and manage both the Kingston Council application and building control.
Assuming the structure is what it appears to be. In 1930s semi-detached and interwar suburban houses on generous plots the load path at a KT3 address is often not where the drawings suggest, and house extensions priced on that assumption produces variations later. GS Renovation opens up and confirms before quoting a New Malden job. An engineer is appointed wherever the design requires one. Ring 07472 424 226 and we will explain how house extensions confirms the load path at a KT3 address first.
It depends on your specific property. Many single storey rear extensions on New Malden's generous interwar plots fall under permitted development, but double storey, wrap-around and larger builds usually need a full planning application to Kingston Council. We assess your KT3 home, its size limits and any prior extensions, then advise the correct route before any work begins.
Yes, across Kingston upon Thames and much of South West London. House extensions take us to Surbiton and the surrounding areas regularly, and a property just outside New Malden is no harder to service than one at KT3. GS Renovation will say plainly if distance makes a job impractical. Email info@gsrenovationltd.co.uk with the address and we will tell you either way. Nothing is owed for asking or for the survey. Aftercare is no harder a few streets further out.
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 New Malden. Explore what else we do locally:
Same Service, Nearby Areas
We carry out house extensions across New Malden and the surrounding areas. Explore a nearby location:
Free, no-obligation quote for house extensions in New Malden. Rated 4.9 from 31 reviews on MyBuilder, fully insured, and building control handled for you.