House Extensions Kew

GS Renovation builds extensions across Kew, working with the Victorian and Edwardian terraces, semis and villas of TW9 near Kew Gardens and the Thames. We handle foundations, steel, roofing and full fit-out, and we tell you honestly whether your project is permitted development or needs a planning application to Richmond Council.

In Kew, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Kew: the structural engineer we appoint designs the structure, we build it, and building control signs it off.

Side-return and rear extensions in Kew

Kew terraces almost always have a narrow side return running alongside the rear closet wing, and filling it in is often the most useful extension a Kew terrace can take. Infilling that strip, often combined with a modest rear extension, turns a cramped galley kitchen into a wide, light open-plan kitchen-diner. We dig proper foundations, allow for the neighbour's drains, and carry the existing wall on a steel beam sized by the engineer.

A wrap-around extension takes the side return and rear together for a larger footprint, while double-storey rear extensions add a bedroom or bathroom above. Whatever the scale, we manage groundworks, the steelwork, the flat or pitched roof with proper insulation, and the glazing, whether that is rooflights, bifold doors or a lantern, so the finished space suits the proportions of your period Kew home.

Housing in Kew

Kew has about 4,470 homes on the Council Tax list: 62% pre-1919, 6% interwar and 31% post-war, with flats making up 43% and houses 57%. A rear extension on a terrace in Kew digs foundations close to both neighbours, so notices to both are normal, and 31% of homes here are terraced.

Basements and Kew's short gardens under Richmond's policy

Richmond's Article 4 Directions on basements and subterranean developments cover the whole of the borough. They were made on 28 February 2017 and confirmed on 12 April 2017, so for a Kew house any basement added with an extension is a planning application, with no permitted development fallback. Richmond Local Plan Policy 54 resists basement development of more than one storey below existing ground level to residential properties, so a single storey is the brief to start from before any other design work is done.

The garden is where Kew schemes meet the limit. Richmond's basement policy limits basements to no more than 50% of the existing garden land, and requires at least 1 metre of naturally draining permeable soil above any basement beneath the garden, with a minimum 200mm drainage layer. On a Kew plot with a short garden, half the garden is not much, and a metre of soil over the basement roof sets both its depth and the finished garden levels. Draw the basement footprint on a measured garden survey before anything else.

Planning and party walls near Kew Gardens

Some Kew extensions fall under permitted development, but many do not, and the difference matters. Parts of TW9 sit within conservation areas near the Gardens, where a single-storey rear extension can still be permitted development within its limits unless an Article 4 direction removes it, but side-return and two-storey extensions need a planning application to Richmond Council, as does work to the front elevation, and a listed building needs listed building consent as well. We assess your specific address at the outset, advise on the likely route, and coordinate the drawings with your designer so there are no costly surprises once we start on site.

Because most Kew houses are terraced or semi-detached, extensions frequently trigger the Party Wall Act where we build up to or astride a boundary, or excavate foundations near the neighbour's wall. We coordinate the work around the party wall award and the timing, and separately we register the building regulations application so building control inspects the foundations, steel, insulation and drainage. Planning and building regs are two different approvals, and we manage both correctly.

Kitchen extensions in Kew

54% of the houses in Kew are terraced. On a terrace the kitchen extension is built out from the back, into the side return where the house has one or across the full rear width, and a steel beam takes the old back wall so the kitchen and the new room become one space. The fit-out is priced on its own page, kitchen renovation in Kew; the build figures are in the table above.

Double storey extensions in Kew

Under permitted development a two-storey rear extension can go no more than 3 metres beyond the original rear wall and must stay at least 7 metres from the rear boundary, and in a conservation area it is not permitted development at all. Many gardens are too short for the 7 metre rule, so a double storey extension in Kew often needs planning permission from Richmond Council. On the 31% of homes that are terraced, the neighbours' windows usually decide the depth. Richmond lists an Article 4 Direction in conservation area CA2 covering Gloucester Road, Kew (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.

• Roof works and structural alterations at roof level
• Brickwork and mortar matched to the existing elevation
• Planning applications and permitted development assessments

VOA Council Tax stock of properties, March 2025, for Kew Gardens. Counts rounded by the VOA.

Before committing to house extensions in Kew, it is worth looking at RSJ and steel beam installation in Kew, house extensions across Richmond upon Thames, wraparound extensions, party walls and extensions, house extensions anywhere in London and Basement Conversion Cost.

Why Choose GS Renovation in Kew

Kew homeowners choose GS Renovation because we build extensions that respect the character of the terrace while adding real, usable space. One team runs the groundworks, steel, roof and fit-out, we are straight with you about permitted development versus a Richmond Council application, and we plan the party wall side along your row with you. That is our founder's 30+ years of building experience.

• Foundation depth set after trial holes, drains and trees are checked
• One point of contact on the phone, not a call centre
• Building control inspected at foundation, damp course and steel stages

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.