Chelsea, Greater London
Glazed rear extension in Chelsea
Glazed rear extension in Chelsea: full-height glass, slim frames and big rooflights for the most open rear room. We measure the house, show you what the rules allow, price it in writing and build it.
We cover Chelsea (SW3, SW7 and SW10) as part of our Greater London work. If your garden in Chelsea faces south, expect us to talk about overhangs and solar-control glass before frame colours.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a glazed rear extension cost in Chelsea?
A glazed rear extension in Chelsea is priced at £3,640–£6,240 per square metre including VAT as a guide, before kitchen fit-out and fees. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £43,500–£75,000 |
| 4 m wide × 6 m deep (24 m²) | £87,500–£150,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a glazed rear extension in Chelsea?
Here is how the rules in England apply to a glazed rear extension in Chelsea.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is within 2 metres of a boundary.
New fabric must meet Approved Document L (2021 edition incorporating 2023 amendments): walls 0.18, roof 0.15 and floor 0.18 W/m²K, windows 1.4 W/m²K or Band B. Under the simple route, new windows, doors and rooflights should not exceed 25% of the extension floor area plus any openings removed; more glass is possible with a whole-house calculation.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Chelsea like to extend?
Period terraces in Chelsea sit alongside flats, and the difference matters: houses usually keep permitted development rights, while flats and maisonettes need planning permission for any rear extension.
How a glazed rear extension in Chelsea comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Glazed rear extensions near Chelsea
We also build glazed and glass-box rear extensions in nearby Battersea (1.1 miles) and Fulham (1.4 miles).
- Glazed rear extension in Battersea
- Glazed rear extension in Fulham
- Glazed rear extension in Pimlico
- Glazed rear extension in Notting Hill
- Glazed rear extension in Shepherds Bush
Other work in Chelsea:
FAQ
Glazed rear extension questions in Chelsea
How much does a glazed rear extension cost in Chelsea?
As a guide, £3,640–£6,240 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £43,500–£75,000 at that rate. Your written price follows the survey.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Is there a limit on how much glass I can have?
In England the simple rule is 25% of the floor area plus openings removed; more is allowed with a calculation showing the house still meets Part L.
Do I need planning permission for a rear extension in Chelsea?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.