Annexe extensions in Greater London
Greater London homeowners can use us for the whole annexe extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide priceFrom £71,500 inc VAT
- PlanningUsually a householder application
- 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
When an annexe extension makes sense
- Homes with a large side or rear garden
- Multi-generational families
- Relatives who need support close by
Accessibility is cheaper to design in than to retrofit. Level access, a 900 mm door width, a level-access shower and space to turn a wheelchair can all be planned into the footprint for little extra cost.
Planning and approvals in Greater London
In England an annexe that stays part of the household and connects to the house is assessed as an extension, but its size usually takes it beyond permitted development, so a householder application describing the ancillary use is the normal route.
The planning position for a specific Greater London address depends on its history and any designations, which is why we check it at the first visit.
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).
Annexe extension prices in Greater London
Prices below are for Greater London, using the London factor of ×1.3. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Greater London: £2,600 to £4,940 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £71,500 – £89,500 | £78,000 – £97,500 | £97,500 – £123,500 |
| One-bedroom annexe 35 m² | £91,000 – £114,000 | £109,000 – £136,500 | £136,500 – £173,000 |
| Larger annexe 45 m² | £117,000 – £146,500 | £140,000 – £175,500 | £175,500 – £222,500 |
Try the guide-price tool to see a range for your own size and finish.
Local to Greater London
Towns we cover in Greater London include Bexley, Barking, Sutton, Croydon, Ilford, Enfield, Harrow, Tottenham. In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
How the project works
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Greater London
Do you cover all of Greater London?
Yes, across the whole of Greater London. Site visits are free and there is no obligation.
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.
Who do I contract with for an annexe extension in Greater London?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How much does an annexe extension cost?
Our guide range is about £2,600 to £4,940 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £109,000 to £136,500 at standard spec in Greater London.
Can the annexe have its own front door?
Yes, many do, but it should still connect to the main house to stay clearly part of it.
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.