What types of house extensions do we build in South East and Greater London?
We shape each extension around the liveable space and resale value it can add to your property, while working within your borough’s planning guidance, boundary rules, and the architectural character your home already has.
Rear extension — a structural addition built across the back of the property and out into the garden, usually to create a bigger kitchen or an open-plan living area.
Side return extension — this fills in the narrow side alley common to Victorian and Edwardian terraces, widening the existing ground-floor rooms.
Wraparound extension — a combined rear and side addition that forms an L-shaped ground floor, adding both width and depth to the house.
Single-storey rear extensions
A single-storey rear extension is still the most common way to get a bright, spacious kitchen-diner or open-plan family space. We remove non-load-bearing partitions, install calculated structural steel beams (RSJs) where needed, and connect the garden to your main living space with flush-threshold bifold or sliding glazing.
Side return and infill extensions
Side return extensions make good use of the narrow, often wasted passageway typical of South East London’s Victorian and Edwardian terraces — the kind of housing stock you’ll find across Greenwich, Lewisham, Bromley, and Dulwich. Filling in this strip can add up to three metres of extra width to your ground floor, turning a cramped galley kitchen into a proper cooking and dining space, often finished with bespoke rooflights.
Wraparound extensions
A wraparound extension combines a side infill with a rear extension to significantly enlarge the whole ground floor. That extra footprint gives you room for a dedicated utility area, a ground-floor shower room, a pantry, or simply more clearly separated zones for cooking, working, and relaxing.
Double-storey and multi-level extensions
A double-storey addition expands your living space downstairs and adds bedroom or bathroom capacity upstairs at the same time. Because the foundation and roof costs are shared across two floors instead of one, the cost per square metre usually works out lower than a single-storey build. If you’re also thinking about the roof space, this pairs well with our loft conversions service, letting you add vertical square footage in the same build programme.
Frequently asked questions about house extensions
How long does a standard house extension take to build in London?
A standard single-storey extension usually takes 10 to 16 weeks of active site work, depending on size and structural complexity.
That splits roughly into 2 to 4 weeks for groundworks, drainage, and foundations; 3 to 5 weeks for structural steel, external brickwork, and getting the roof weathered in; and 5 to 7 weeks for first- and second-fix electrics, plumbing, plastering, glazing, and the interior fit-out. Before any of that starts on site, expect another 8 to 12 weeks for design, structural calculations, and statutory approvals.
Can we remain living in our home during the extension build?
Yes, in most cases — for single-storey rear or side-return extensions, we seal off the active construction area with dust screens and temporary weatherproofing so the rest of the house stays liveable.
The one stage that can disrupt daily life is when we open up an existing load-bearing wall to fit steel beams; you may need a temporary kitchen setup or a few adjusted routines for a short period. For bigger wraparounds or multi-level projects where the main services get interrupted, we’ll talk you through the logistics well in advance so you can plan around it.
What happens if my property is located within a designated Conservation Area?
Permitted Development rights are more restricted in Conservation Areas, so you’ll generally need full planning permission with exterior materials that closely match the existing building.
We prepare heritage statements, detailed elevation drawings, and material schedules tailored to satisfy your local council’s conservation officers. That lets us balance modern touches — slimline aluminium glazing, zinc cladding — with the character of the surrounding street.
What happens if a neighbouring property refuses to sign a Party Wall Notice?
A refusal, or simply no response, doesn’t stop your project — it triggers the formal appointment of either an agreed Party Wall Surveyor or two independent surveyors, who issue a legally binding Party Wall Award.
The surveyor records a schedule of condition for the neighbouring property and sets enforceable working hours and protective measures. Once the Award is served, construction can go ahead lawfully under its terms.
What warranties and guarantees do we provide upon project completion?
You get a formal 10-year structural warranty, plus the statutory Building Control Completion Certificates and manufacturer guarantees on any glazing, roofing membranes, and mechanical systems we install.
That warranty is your confirmation that the foundations, load-bearing steelwork, and any structural alterations meet the structural integrity requirements set out in UK Building Regulations.
