Home office extensions in Chelsea: design, approvals and build
A home office extension in Chelsea starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in ChelseaFrom £20,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time8–12 weeks on site
- Postcode districtsSW1W, SW1X, SW3, SW5, SW7

Guide prices for Chelsea
Prices below are for Chelsea, using the London factor of ×1.3. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Chelsea: £2,400 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 3.2 m 8 m² | £20,500 – £25,000 | £22,000 – £28,500 | £28,000 – £35,500 |
| 3 m × 3.6 m 11 m² | £26,000 – £31,500 | £30,500 – £39,000 | £38,500 – £49,000 |
| 3 m × 5 m 15 m² | £36,000 – £43,000 | £41,500 – £53,000 | £52,500 – £66,500 |
Try the guide-price tool to see a range for your own size and finish.
Planning and approvals in Chelsea
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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).
Who a home office extension suits
- Homes where a loft or garden room is not practical
- People who work from home most of the week
- Households that need a second quiet room
North-facing glass and rooflights give steadier light for screen work. Where the office faces south, we use deeper reveals or external shading to keep glare and heat down.
Local to Chelsea
We cover Chelsea and the postcode districts SW1W, SW1X, SW3, SW5, SW7, SW10. We also work in nearby Battersea (1 mile), Fulham (1 mile), Notting Hill (2 miles), Shepherds Bush (3 miles).
Just over the Surrey border, East Molesey is about 10 miles away. 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.
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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.
Home office extension questions answered
How long does a home office extension take to build in Chelsea?
On site, typically 8 to 12 weeks once approvals are in place. Before that, allow 4–10 weeks design and approvals.
Do you cover all of Chelsea?
Yes. We cover Chelsea and the surrounding parts of Greater London. Site visits are free and there is no obligation.
Do I need building regulations approval in Chelsea?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I claim the cost against tax?
Building work on your home is not normally an allowable business expense, and claiming it can have capital gains tax effects. Speak to an accountant before assuming any tax relief.
Is an attached office better than a garden office?
An attached office shares the house heating and broadband, adds floor area to the home, and needs no garden path in the rain. A garden building can be cheaper and quicker but is a separate structure.
Book a free site visit in Chelsea
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.