Chelsea bungalow extensions, designed and built
We design and build bungalow extensions for houses in Chelsea, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in ChelseaFrom £34,000 inc VAT
- PlanningSingle storey often permitted development
- Build time10–18 weeks on site
- Postcode districtsSW1W, SW1X, SW3, SW5, SW7

Local to Chelsea
Our survey diary covers Chelsea, including SW1W, SW1X, SW3, SW5, SW7, SW10. Nearby, we also take on projects in 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.
Planning rules that apply in Chelsea
In England a single-storey extension to a bungalow follows the normal permitted development limits (3 m or 4 m, or 6 m and 8 m through prior approval). Adding a first floor always needs planning permission.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
What should I budget for a bungalow extension in Chelsea?
For Chelsea 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 Chelsea: £2,280 to £4,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 5 m 15 m² | £34,000 – £41,000 | £39,500 – £52,000 | £50,500 – £66,500 |
| 4 m × 6 m 24 m² | £54,500 – £66,000 | £63,500 – £83,000 | £81,000 – £106,500 |
| L-shape 35 m² | £79,500 – £96,000 | £93,000 – £121,000 | £118,000 – £155,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Who a bungalow extension suits
- Families wanting more space on one floor
- Bungalows on larger plots
- Homeowners planning for later life
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
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about bungalow extensions
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Chelsea, 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 bungalow extension take to build in Chelsea?
On site, typically 10 to 18 weeks once approvals are in place. Before that, allow 6–14 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.
Can I extend a bungalow without planning permission?
In England a single-storey rear extension to a bungalow follows the same permitted development limits as a house: 3 m or 4 m, or up to 6 m or 8 m through prior approval. Adding a storey always needs planning permission.
Is it better to extend sideways or upwards?
Sideways and rearwards is usually simpler, cheaper and keeps single-level living. Upwards saves garden but means stairs, more structure and planning permission.
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.