Single and double storey extensions in Edgware. Trusted, professional, 30+ years' hands-on experience.
GS Renovation designs and builds extensions throughout Edgware and HA8, making the most of the generous plots that came with its 1930s and interwar houses. With over 30 years of experience across Barnet, we handle everything from single-storey rear additions to double-storey and wrap-around builds on these suburban semis and detached homes.

Edgware's interwar semis and detached houses were built on generous plots, which gives real scope for extending. A single-storey rear extension opens the back of the house into a large kitchen-diner, while a side return or side infill uses the space alongside the house that many 1930s plots enjoy. A wrap-around combines both, and a double-storey extension can add a bedroom and en-suite above the new ground-floor room.
We start with the groundworks, digging and pouring foundations suited to the local ground and any nearby trees, then build the walls, install the steel beams that carry the openings, and complete the roof. Throughout, we manage the full fit-out, including plastering, electrics, plumbing, flooring and decoration, so your Edgware extension is finished properly rather than left as a shell for other trades.
Whether your Edgware extension needs a full planning application or falls under permitted development depends on the property. Many single-storey rear extensions on interwar semis can proceed under permitted development rights, subject to size, height and boundary limits. Larger builds, double-storey additions, or work on a property in a conservation area or with restricted rights usually require a full planning application to Barnet Council.
We assess your specific house and plot before committing to a route, and we prepare and submit the application to Barnet Council where one is needed. The structural work is covered separately by building regulations, with building control inspecting the foundations, steel and drainage. Where an extension sits near or on the shared party wall of a semi, we also handle the party wall notices to your neighbour.
Edgware homeowners choose GS Renovation because one team takes the extension from foundations to final coat. We advise honestly on permitted development versus a Barnet Council planning application, install engineer-sized steel, coordinate building control and finish the space fully. With 30+ years extending HA8 homes, we understand these interwar plots and how far they can go.
Punctual, worked hard, and did exactly what he was asked and what he said he would do. Overall, a very high quality job. Will use again.
Very friendly and I am very pleased with the work he has done, also very clean worker and enthusiastic about his work. Can not fault this company!!!!…
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
FAQ
It can, and we would rather say so before quoting. In a 1920s and 1930s suburban home the unknowns behind plaster are what move a house extensions figure, which is why the HA8 survey matters more here than on a new estate. GS Renovation prices the visible work, names the risks, and agrees anything additional with an Edgware homeowner in writing. That is standard across Barnet. Ring 07472 424 226 and we will describe the checks an HA8 property needs. 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.
Barnet's draft design guidance sets 3 metres for a terraced house, 3.5 metres for a semi detached house and 4 metres for a detached house. Policy CDH05 then asks that extensions complement the character of the existing building in style, form and materials and stay subordinate in size, scale and height. It also requires a sympathetic roof profile and amenity space kept above the Table 10 standard. Permitted development can allow more, but the two routes are assessed differently.
Yes, tree roots in shrinkable London Clay govern foundation depth, and a protected tree adds a consent step on top. Around 150 tree preservation zones on the national register name an Edgware address, including 261 Hale Lane made on 30 October 2008, Bury Farm on Edgwarebury Lane from 1979 and the Broadwalk Shopping Centre car park from 2023. Every sampled point across Edgware returns London Clay Formation bedrock, so footings near a mature tree are deepened on the engineer's advice.
It can, because a flood risk point check at Edgware town centre returns both Flood Zone 2 and Flood Zone 3 records from the Environment Agency. Barnet's Local Plan confirms parts of the station site are in Flood Zone 3 and at surface water flood risk, and paragraph 4.18.10 describes the town centre as in effect surrounded by floodplains. Where a site falls in Zone 2 or 3, the application needs a flood risk assessment and finished floor levels set accordingly.
None is mapped, because a 63 point grid across Edgware found no artificial ground recorded at all at 1:50,000 scale and no superficial deposits except alluvium in the brook corridors. That does not remove the need for trial holes, since garden scale infill, old ponds and buried garden waste sit below the resolution of national mapping. The practical answer is that footings are designed on what the trial hole shows, not on the map.
Not automatically, but the conservation area appraisal lists additions and extensions among the unsympathetic alterations already harming the estate, alongside replacement windows and doors, added porches, cladding and rendering, dormers and roof extensions and fake timber framing. It also records front gardens set back behind low brick walls or hedges, with specimen trees planted on boundaries that open or terminate views. A rear extension that leaves the front boundary and street view untouched has the better chance.
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 Edgware. Explore what else we do locally:
Same Service, Nearby Areas
We carry out house extensions across Edgware and the surrounding areas. Explore a nearby location:
Free, no-obligation quote for house extensions in Edgware. Rated 4.9 from 31 reviews on MyBuilder, fully insured, and building control handled for you.