The 10 extension builders from Google's results for London, ranked on Google rating, online presence and other factors. Updated 10 September 2026.
on GoogleLondon
Gls Building Contractors handles house extensions and structural building work for properties across London. Work focuses on altering layouts and improving space within residential buildings.
07878 660706 66 Grange Rd, London W5 5BX
on GoogleLondon
Alstruct Ltd provides house extensions, loft conversions and basement conversions for homeowners in Chiswick and West London. Its services also include groundworks, full property renovations and garden landscaping.
020 8080 8240 15B Raven Rd, London E18 1HB
on GoogleLondon
2pm Architects creates architectural designs for residential extension projects throughout Greater London. Working on rear, side, and wraparound structures, the practice assists householders seeking to enlarge kitchen areas and overall living space.
020 3920 9805 45 Dresden Rd, London N19 3BG
on GooglePopes Dr, London
LCCL Construction is a design and build company converting lofts, extending houses and renovating homes across East London. It works in areas such as Hackney, Walthamstow, Leyton and Bow, where much of the housing is Victorian terraces, and provides architectural design as part of its service.
020 8037 7332 3rd Floor, Hathaway House, Popes Dr, London N3 1QF
on GoogleLondon
Simply Extend builds house and kitchen extensions across East and South London, covering areas such as Croydon, Lambeth and Wandsworth. The business manages residential builds through assigned project managers, handling groundworks, brickwork construction, plastering and internal fittings.
on GoogleLondon
Build Team provides integrated design and construction services for residential extensions throughout London. The team works on kitchen additions, rear and side return builds, wraparound structures, and loft conversions.
020 7495 6561 342 Clapham Rd, London SW9 9AJ
London
London House Extension plans and constructs single and double-storey house extensions across London. Operating from the W11 area, the business provides project management and build services to expand residential living spaces.
London
London house extensions is an extension builder based in London.
London
Plus Rooms provides house and kitchen extension services to homeowners in Richmond-upon-Thames and across South West London. The company manages projects from design through to construction, handling planning regulatory requirements along the way. Its team also builds loft conversions.
London
Simply Construction Group carries out residential building projects across Richmond and Bromley. The firm handles architectural design through to construction delivery, specialising in home extensions, loft conversions and basement conversions for local property owners.
In London, single storey, per m² typically costs £2,200 – £3,100. Labour in Greater London runs 22% above the UK median, which accounts for most of the difference from the same job elsewhere.
These are the firms from Google's results for "house extensions london". They are ranked on Google rating, online presence and other factors.
The figures above are London ranges. These explain what drives them, so you can read a quote properly.
Per-square-metre prices for single-storey, two-storey, side return and kitchen extensions, costs by size, the fees outside the build price, and planning limits by nation.
The permitted development limits for extensions, lofts, porches and outbuildings in England, where the rights do not apply, what prior approval and a certificate cost, and how Wales, Scotland and NI differ.
When the Party Wall Act applies, which notice to serve and how far ahead, what your neighbour can do, what a surveyor's award costs, and the rules in Scotland and NI.
Under permitted development, three metres for a terrace or semi and four for a detached, doubled to six and eight under the prior approval process. Height, materials and how much garden you cover all carry separate limits, and none of it applies in a conservation area.
If you are excavating within three metres of a neighbour's foundations or building on the boundary, yes. You must serve notice two months before work starts. Skipping it is the most common reason extension projects stall.