House Extensions Twickenham
Single storey rear and double storey extensions in Twickenham, planning, structure and build under one contract.
- Rated 4.9 from 31 reviews on MyBuilder
- Single-storey rear extension from £40,000
- Free site survey, itemised quote
GS Renovation builds extensions across Twickenham, from side-return infills to full wrap-arounds on the Victorian and Edwardian terraces near the Thames. We take your extension from groundworks and steel through to a finished, fitted space.
In Twickenham, 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 Twickenham: the structural engineer we appoint designs the structure, we build it, and building control signs it off.
Price guide
| Work | Indicative London range |
|---|---|
| Single-storey rear extension | from £40,000 |
| Rear extension, per m² | £2,000 to £2,800 |
| Side return, per m² | £2,400 to £3,200 |
| Wraparound, per m² | £2,400 to £3,200 |
| Double storey, per m² | £1,800 to £2,600 |
| Basement extension | see the basement page |
Indicative London ranges (Architecture for London, Resi, MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: Extension Costs & Planning.
Quick estimate for Twickenham
Twickenham range: choose above
Side-return extensions on Twickenham terraces
The narrow side return alongside a Twickenham terrace is often wasted outdoor space, and infilling it is one of the most effective ways to widen a cramped kitchen. We dig and pour new foundations next to the existing footings, tie the new structure into the original brickwork and install steel beams to carry the wall we remove. The result is a bright, full-width kitchen-diner running the depth of the house.
Rear and wrap-around extensions take this further, extending into the garden and around the closet wing that many of these houses were built with. We handle the groundworks, the drainage diversions around existing manholes, the roof, whether flat with a lantern or pitched, and the full fit-out. Because the plots in TW1 vary, we set out each design around your boundaries, the light and how you actually want to use the space.
Housing in Twickenham
Twickenham's housing, as the Council Tax list records it, is about 14,480 homes: 59% houses, 41% flats, with 38% pre-1919, 35% interwar and 26% built since 1945. A rear extension on a terrace in Twickenham digs foundations close to both neighbours, so notices to both are normal, and 33% of homes here are terraced.
Planning an extension on a Twickenham conservation area street
Twickenham Riverside Conservation Area number 8 is one of 85 conservation areas in the London Borough of Richmond upon Thames. In Richmond conservation areas, front and side extensions of one storey or more and two storey rear extensions are among works needing planning permission. For a Twickenham terrace inside one, that puts a side return infill in the application category. Richmond's target to determine householder and small scale planning applications is 8 weeks, so an infill wanted for spring needs its drawings ready in winter.
Building control is charged by size band. Richmond's standard domestic charges separate an extension under 40 square metres from one over 40 and under 60 square metres, and on a Full Plans application for the smaller band the charge is split between a plan fee and an inspection charge. Separately, Richmond's CIL Charging Schedule sets residential rates in a higher and a lower band. A modest Twickenham rear extension may never be liable, but a large wrap-around should be checked early, and any relief claimed before work starts.
Planning and permitted development in Twickenham
Some Twickenham extensions fall under permitted development and do not need a full application, while others require planning permission from Richmond Council, and the difference depends on the size, the position and whether your home sits in a conservation area or is listed. We assess this before design and are honest about which route your property needs, so you are not surprised partway through.
Where planning permission is required, we coordinate the drawings with your designer and support the application through the process. Every extension also needs building regulations approval for the foundations, structure, insulation and drainage, which is separate from planning. On the shared boundaries typical of TW1 terraces, party wall notices to the neighbours usually apply too; you serve them as the building owner, we give you the drawings they need, and we set all of this out clearly at the start.
Kitchen extensions in Twickenham
56% of the houses in Twickenham 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 Twickenham; the build figures are in the table above.
Double storey extensions in Twickenham
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 Twickenham often needs planning permission from Richmond Council. On the 33% of homes that are terraced, the neighbours' windows usually decide the depth. Richmond lists an Article 4 Direction in conservation area CA47 covering Queen's Road, Twickenham (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.
- Wrap-around extensions and infills
- Foundations, groundworks and steel frames
- Scaffolding, site set-up and safe access on tight terraced plots
VOA Council Tax stock of properties, March 2025, for Twickenham Marble Hill, Twickenham North, Twickenham Town and Twickenham West. Counts rounded by the VOA.
Why Twickenham Homeowners Choose GS Renovation
Homeowners across Twickenham choose GS Renovation because one accountable team carries the whole extension, the foundations, the steelwork, the roof, the planning route and the fit-out, rather than juggling separate trades. We know how these TW1 terraces are built, we work tidily around occupied homes, and our founder's 30+ years on the tools means the finished space is built properly and to last.
- Waste cleared as we go, not left piled up outside
- Foundation depth set after trial holes, drains and trees are checked
- Building control inspected at foundation, damp course and steel stages
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
George always kept to commitments and arrived on time. He offered helpful suggestions during his initial visit and promptly provided a reasonably…
It's the second time I have hired George and he has been absolutely professional and the work he did resembles perfectly what I had in mind. Being an…
FAQ
Frequently Asked Questions about House Extensions Twickenham
What should I budget for house extensions in Twickenham?
Setting a house extensions budget in Twickenham works best from a scoped quotation within £2,000 to £2,800 per m² for a rear extension (indicative), not from a headline rate. Once the TW1 property has been surveyed, GS Renovation can say what the job involves there, including the order it must follow: drainage under the footprint is diverted before foundations are poured. Every line is itemised so the budget holds. Email info@gsrenovationltd.co.uk to book the survey.
Does my Twickenham extension need planning permission or is it permitted development?
Many rear and side-return extensions in Twickenham are permitted development, but larger schemes, or side-return infills in a conservation area, need planning permission from Richmond Council, and listed homes need listed building consent. Either way the work needs separate building regulations approval. We check your specific address and constraints before design and tell you honestly which route applies.
Do trees near my Twickenham garden change the extension foundations?
They can. On shrinkable soils, roots draw moisture from the ground and cause movement, so footings near trees are taken deeper. The engineer checks the soil type and the species and distance of nearby trees before setting the depth. Richmond Council's building control inspects the trench. Deeper footings near the neighbour's house can also bring in the three-metre party wall notice.
Can we fill the side return of our Twickenham terrace?
Usually, and it is a common way to widen the kitchen. The side return often carries rainwater and waste pipes, which are diverted before foundations, with falls agreed under Part H. The new roof usually bears onto a steel along the closet wing wall. If you build up to the boundary, excavation near next door needs one month's party wall notice.
What does Part L mean for a glazed Twickenham extension?
The walls, roof and floor must meet current insulation standards, and large glazed areas count against that. Wide folding doors and a roof lantern can be combined, but the design has to show the overall heat loss meets the standard. Building control checks the calculations. Deciding the glazing early saves redrawing the extension later.
Does a conservation area change extension rights for a Twickenham house?
Yes. In a conservation area, the permitted development rights for side extensions are removed, so a side return infill needs planning permission from Richmond Council. Rear extensions within permitted development limits may still be possible, and building regulations apply either way. Check the street's status before design work begins.
Does a Twickenham extension need checking against Richmond's Article 4 list?
Yes. Richmond lists its directions by conservation area and street, including one in CA47 covering Queen's Road, Twickenham. Richmond's list of changes that can need planning permission under a direction includes extensions and additions. There are also borough wide directions on basements and subterranean developments. Checking the address against the list takes minutes and, with the conservation area check, tells you whether an extension can go ahead under permitted development at all.
Is pre-application advice from Richmond worth getting for a Twickenham extension?
It can be, if you know what it includes. Richmond's category 6 householder pre-application advice does not include a meeting with a planning officer, so the result is a written response to the drawings. That suits a side infill on a conservation area street where the question is height or materials. It suits less a scheme where you want to talk options through, and there a designer with local planning experience may get you further, faster.
How long should a Twickenham extension allow for building control approval of drawings?
Richmond decides a Full Plans application within five weeks, or two months if the applicant requests an extension of time. Where the design is settled, run it alongside the planning period rather than after it, so the structural drawings are approved by the time permission arrives. Then give Richmond building control 2 days notice that you intend to commence works, and the groundworks can start on the date the digger is booked.
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