House Extensions Surbiton
Single storey rear and double storey extensions in Surbiton, 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 plans and builds extensions across Surbiton, adding kitchen extensions and extra rooms to the Victorian and Edwardian houses of KT6 without losing their character. We handle groundworks, steel, roof and fit-out as one managed project.
In Surbiton, 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 Surbiton: 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 Surbiton
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Kitchen extensions and side returns in Surbiton
The project Surbiton owners ask about most is a kitchen extension. On a terrace that usually means filling in the side return, that narrow alley of wasted ground beside the rear closet wing, and pushing out at the rear; on a semi or detached villa it is a single storey rear extension across the back. Either turns a cramped galley into an open-plan kitchen-diner that runs the full width of the house. We dig and pour the foundations, tie the new walls into the existing Victorian brickwork and carry the load on a steel beam where the old outside wall comes down.
Double-storey rear extensions add a bedroom or bathroom above the new ground floor, which suits families staying put in KT6 rather than moving on. We match brick, pointing and roof detail to the original house so the addition reads as part of the house. Rooflights and glazing bring daylight deep into a plan that was previously dark at its centre, a common problem in these long, narrow properties.
Housing in Surbiton
Take the 7,740 or so homes the valuation list gives Surbiton: 78% flats, 22% houses, 34% from before 1919, 10% interwar and 56% post-war. Since most homes here are flats, a flat in Surbiton has no householder permitted development rights, so extending one needs planning permission and the freeholder's consent.
Why Surbiton flats cannot extend the way houses can
78% of homes in Surbiton are flats and 22% are houses. That split matters for extensions, because the permitted development rights for householder extensions belong to houses, not flats, so any extension to a Surbiton flat needs a planning application. A ground floor flat in a divided villa that wants a rear kitchen extension usually also needs the freeholder's consent, since the new structure ties into walls and foundations the freeholder owns. The flats above may object to losing light or outlook, so their views are worth hearing before the drawings are finished rather than after the application is made.
Once an application is needed, Kingston's Residential Design SPD sets the frame: single storey rear extensions should generally not exceed 3 to 3.5m in depth, and in all cases at least 50% of the rear garden should remain. In a divided villa the garden is often split between flats, so find the lease plan showing which part belongs to your flat before the architect starts, because the 50% test is best argued from the garden the flat actually has. We check the depth, the remaining garden and the roof height against the SPD before any structural design is commissioned.
Planning and party walls in Kingston
Some Surbiton extensions fall under permitted development, while others need a full planning application to Kingston Council, and the difference depends on your specific property. Size, height, how far you project and whether the house sits in a conservation area or has been extended before all matter. In a conservation area a single storey rear extension can still be permitted development, but side and two-storey extensions need permission, and flats, which are most Surbiton homes, have no permitted development at all. We assess your house honestly, tell you which route applies and coordinate the drawings and application with your architect or designer when planning permission is genuinely required.
Because Surbiton terraces share party walls, an extension that ties into next door's flank wall, or excavates foundations close to it, brings the Party Wall Act into play. You serve the correct notices as building owner, or your surveyor does, and any schedule of condition is recorded through that process before we break ground; we give you the drawings the notices need and build to any award. Separately, the structural elements, the beams and the foundations, are covered by building regulations and inspected by building control regardless of whether planning consent was needed.
Double storey extensions in Surbiton
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 Surbiton often needs planning permission from Kingston Council. It is a job for the 22% of homes that are houses; a flat cannot add a storey this way. Surbiton Town Centre Conservation Area was designated in June 1991 and has 311 properties over 5.2 hectares (council source). Our double storey extension page explains the build, at £1,800 to £2,600 per m² across both floors.
- First fix and second fix plumbing and electrics throughout
- Side-return and rear extensions
- Brickwork and mortar matched to the existing elevation
VOA Council Tax stock of properties, March 2025, for Surbiton North and Surbiton South. Counts rounded by the VOA.
The GS Renovation Difference in Surbiton
Homeowners across Surbiton choose GS Renovation because one team carries the whole extension, from the first trial hole to the last coat of paint. We know how KT6 houses are built, when Kingston Council planning is needed and when permitted development covers it, and how to keep a party wall neighbour onside. Our founder's 30+ years of work stands behind every extension.
- Permitted development checked before you pay for a planning application
- Fully insured, with cover in place on every site
- Foundation depth set after trial holes, drains and trees are checked
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
George was brilliant. Lovely bloke, very reasonably priced and a perfectionist to boot. He completed our small kitchen renovation with care and great…
George always kept to commitments and arrived on time. He offered helpful suggestions during his initial visit and promptly provided a reasonably…
FAQ
Frequently Asked Questions about House Extensions Surbiton
Is a cheap house extensions quote in Surbiton worth taking?
Be careful with a cheap house extensions quote in Surbiton, particularly if nobody has visited. Pricing a post-war block home unseen is how a low figure becomes a high one halfway through, because the depth of neighbouring Surbiton foundations decides how deep the new footings go. GS Renovation surveys, itemises within £2,000 to £2,800 per m² for a rear extension (indicative) and holds the total. A second opinion on the KT6 quotation costs nothing.
Will my Surbiton side-return extension need planning permission from Kingston Council?
Many single-storey side-return and rear extensions in Surbiton are permitted development, but larger schemes, double-storey additions, or homes in a conservation area or already extended may need a full planning application to Kingston Council. We assess your house, confirm the route and coordinate the application with your designer if required. Either way, the foundations and steelwork need building regulations approval.
Can a Surbiton flat be extended without planning permission?
No. Those householder rights, including the single-storey rear allowance, were written for houses and do not extend to flats or maisonettes. With flats forming 78% of Surbiton's dwellings, most owners asking this need a full application to Kingston Council. The lease almost always gives the freeholder a veto over new structure too, and building regulations approval is required on top of both.
Do neighbours need notice when foundations are dug for a Surbiton extension?
Often. Where the trench comes within 3 metres of the neighbour's building and goes deeper than its foundations, they must receive one month's notice before digging. They can agree, or dissent and appoint surveyors. Building next to or on the boundary line brings further notices.
Does being near the Thames affect extension foundations in Surbiton?
It can. Ground close to the river may be softer, or hold water nearer the surface, than ground further up the hill, and that changes how deep a foundation goes or whether a different type is needed. Trial holes dug before the design is fixed show what is actually there, so the engineer designs to real conditions. Building control then inspects the trench before any concrete is poured.
What insulation standard must a Surbiton extension meet?
Current Part L standards for its walls, floor and roof, however old the house it joins. That fixes how thick the build-up becomes and limits how much glass the design can carry before the heat loss calculation fails. A rooflight or lantern placed near the old rear wall can still bring daylight into the middle of the house, provided the figures allow it.
How tall can a single storey rear extension to a Surbiton house be?
Where it needs planning permission, Kingston's Residential Design SPD says a single storey rear extension with a flat roof should not exceed 3m in height, a parapet roof 3.3m and a pitched roof 4m. On a Surbiton villa with tall ground floor ceilings, a flat roof held to that height can sit well below the old ceiling line, so the new room's ceiling steps down where it meets the house. The structural engineer we appoint sizes the steel over the opening with that step in mind, since a deep beam eats into the little height there is.
Do Surbiton's Local Areas of Special Character restrict house extensions?
Not through permitted development. Kingston lists Berrylands Road, Cleaveland Road, The Mall, Cranes Park, Grand and Elmbridge Avenue, St Matthews Avenue and Walpole Road as Local Areas of Special Character in Surbiton, and says permitted development rights are not affected in them. An extension that fits permitted development there proceeds as it would elsewhere. If the scheme goes further, the application is judged on a street Kingston Council has picked out for its character.
Would an extension to a Surbiton house be liable for CIL?
For a typical single storey addition, no. Kingston's CIL guidance says a domestic single storey extension of 30 square metres is not CIL liable because the extension is less than 100 square metres. Kingston's charging schedule sets residential rates by zone, from zone one to zone four, so the zone of your address matters on a larger scheme or where a new dwelling is created. Check it before the permission is implemented, not after.
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