Single-storey rear extensions in Greater London
A single-storey extension in Greater London starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide priceFrom £27,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Towns covered105
- Site visitFree, no obligation
Towns in Greater London
- Abbey Wood
- Acton
- Barking
- Barnes
- Barnet
- Battersea
- Beckenham
- Becontree
- Bethnal Green
- Bexley
- Blackheath
- Bow
- Brixton
- Brockley
- Camden Town
- Canning Town
- Carshalton
- Catford
- Chalk Farm
- Chelsea
- Chessington
- Chingford
- Chislehurst
- Chiswick
- Coulsdon
- Cricklewood
- Croydon
- Dagenham
- Earlsfield
- East Barnet
- Edmonton
- Eltham
- Enfield
- Enfield Lock
- Feltham
- Finchley
- Friern Barnet
- Fulham
- Golders Green
- Greenford
- Greenwich
- Hampton
- Hanworth
- Harlesden
- Harringay
- Harrow
- Hayes (Hillingdon)
- Heston
- Highbury
- Holloway
- Hook
- Hornchurch
- Hounslow
- Ilford
- Isleworth
- Kilburn
- Leytonstone
- Manor Park
- Mitcham
- Morden
- Muswell Hill
- New Cross
- New Malden
- Norbury
- Northolt
- Notting Hill
- Orpington
- Palmers Green
- Peckham
- Pinner
- Plumstead
- Ponders End
- Purley
- Putney
- Richmond
- Roehampton
- Romford
- Ruislip
- Shepherds Bush
- South Croydon
- South Norwood
- South Ruislip
- Southall
- Stamford Hill
- Stepney
- Stratford
- Streatham
- Surbiton
- Sutton
- Thamesmead
- Tooting
- Tottenham
- Upper Norwood
- Uxbridge
- Wallington
- Walthamstow
- Wealdstone
- Welling
- Wembley
- West Ham
- Willesden
- Wimbledon
- Wood Green
- Woodford Green
- Worcester Park
Is a single-storey extension right for your house?
- Homeowners who want open-plan living onto the garden
- Semi-detached and detached houses with a usable rear garden
- Terraced houses that want a deeper kitchen across the full width
Depth is the big decision. Every extra metre adds floor area but also takes garden and can push you out of permitted development. We draw the room at two or three depths so you can see the trade-off in space, light and cost before anything is fixed.
Extensions in and around Greater London
Towns we cover in Greater London include Bexley, Barking, Sutton, Croydon, Ilford, Enfield, Harrow, Tottenham. London's housing is dominated by Victorian and Edwardian terraces, many with a rear outrigger and a side return, and 1930s semis in the outer boroughs. Conservation areas are common, so the planning check comes first.
Do I need planning permission in Greater London?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
What should I budget for a single-storey extension in Greater London?
For Greater London we adjust our national guide rates by ×1.3, the factor we use for London. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Greater London: £2,280 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £27,000 – £32,000 | £31,500 – £41,000 | £40,500 – £53,500 |
| 4 m × 5 m 20 m² | £45,500 – £53,500 | £53,000 – £68,000 | £67,500 – £88,500 |
| 5 m × 6 m 30 m² | £68,000 – £80,000 | £79,500 – £101,500 | £101,000 – £133,000 |
For a figure based on your own dimensions, use our guide-price tool.
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions people ask about single-storey extensions
Will my neighbours in Greater London be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Greater London, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does a single-storey extension take to build in Greater London?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
How deep can a single-storey rear extension be without planning permission?
In England, up to 3 m beyond the original rear wall on a semi-detached or terraced house and 4 m on a detached house, within height and boundary limits. Through the larger home extension prior approval scheme those depths rise to 6 m and 8 m. Wales, Scotland and Northern Ireland use their own rules, which we check for your address.
Flat roof or pitched roof?
Flat roofs give more headroom inside and suit lanterns and rooflights; pitched roofs can blend better with older houses. Both meet building regulations when built properly. See our flat roof and pitched roof pages for the details.
Book a free site visit in Greater London
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.