Single and double storey extensions in Hampstead. Trusted, professional, 30+ years' hands-on experience.
GS Renovation designs and builds extensions throughout Hampstead, working with the bay-fronted Victorian and Edwardian terraces of NW3 and the larger villas nearer the Heath. Drawing on more than 30 years in North London, we take on the foundations, the steelwork, the roof and the full fit-out, so your new space is built once and built properly.

The classic Hampstead extension fills the side return alongside the rear closet wing, widening a narrow kitchen into a bright open-plan room facing the garden. We dig and pour the foundations, allowing for the mature trees and clay ground common across NW3, then form the new walls and roof. A steel beam sized by the engineer carries the original rear wall once it opens into the new floor area.
Wrap-around extensions take that side return and combine it with a rear projection to transform the ground floor of a terrace. Double-storey schemes add a bedroom or en-suite above. On homes near the village conservation area, external changes are handled sensitively, matching brick, pointing and window details so the addition sits comfortably against the period frontage rather than looking bolted on.
Whether your extension is permitted development or needs a full planning application depends on the property. A modest single-storey rear extension may fall under permitted development, but homes in the Hampstead conservation area, or any listed building, usually need permission from Camden Council, and larger or double-storey schemes almost always do. We advise honestly on which route yours takes before you commit to a design.
Because your extension builds off or against a shared boundary, the Party Wall Act typically applies, so notices go to the neighbour before we break ground. Alongside that, every extension is inspected under building regulations for foundations, structure, insulation and drainage. We coordinate the drawings, the party wall steps and the building control inspections so the whole project moves as one across NW3.
Hampstead homeowners choose GS Renovation because we handle the extension end to end, from groundworks and steel to roofing, glazing and the final decoration. We are candid about whether you need planning permission or permitted development, we manage the party wall notices, and 30+ years in the borough means we build to suit these period terraces and villas.
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
Every Hampstead project is priced on its own merits, as the cost of house extensions varies with the size, specification and condition of the home. We give a clear, itemised quote up front with no obligation. Call 07472 424 226 for an estimate tailored to your property. 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.
How long house extensions takes in Hampstead depends on the size of the job, but we always agree a programme before starting and stick to it, keeping you informed from the first day to the last.
Hampstead homeowners choose GS Renovation for reliability and quality. We are fully insured, building control compliant where needed, and bring over 30 years of hands-on experience to every house extensions project, with a single point of contact throughout.
Many single-storey rear extensions in Hampstead 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 Hampstead's homes are Victorian and Edwardian terraced properties, and we renovate them regularly. We plan each house extensions around their particular characteristics, such as solid brick walls, rear closet wings, side returns and original period features, so the result suits the building and meets building control.
It depends on the house. A single-storey side-return may be permitted development, but much of Hampstead sits within a conservation area and many homes are listed, which usually means a planning application to Camden Council. Double-storey and larger schemes generally need permission too. We assess your specific property, advise on the likely route and handle the drawings and applications.
Yes, Hampstead is one of our core areas. We work on every street and the NW3 area and across the wider North London, so wherever your home is, call 07472 424 226 and we will confirm we can help.
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 Hampstead. 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 Hampstead and the surrounding areas. Explore a nearby location:
Contact GS Renovation today for a free, no-obligation quote for house extensions in Hampstead.
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