Chelsea glass extensions, designed and built
Thinking about a glass extension for your Chelsea home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide price in ChelseaFrom £39,000 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Build time10–16 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: £3,900 to £7,540 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £39,000 – £47,000 | £39,000 – £49,500 | £44,500 – £60,500 |
| 3 m × 4 m 12 m² | £46,500 – £56,500 | £54,500 – £69,000 | £67,000 – £90,500 |
| 3 m × 6 m 18 m² | £70,000 – £84,500 | £81,500 – £103,000 | £100,500 – £136,000 |
For a figure based on your own dimensions, use our guide-price tool.
Who a glass extension suits
- Small infill spaces and side returns
- Garden-facing dining rooms
- Period and listed-style houses where a light touch is wanted
Planning rules that apply in Chelsea
In England a glazed or orangery-style extension follows the same size limits as any single-storey rear extension: 3 m or 4 m without an application, or up to 6 m and 8 m through prior approval. Building regulations limit glazing to about a quarter of the new floor area plus the openings it replaces, unless whole-house calculations show the design still performs.
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.
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.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Working in Chelsea
Across SW1W, SW1X, SW3, SW5, SW7, SW10, we can visit, measure and advise. Nearby, we also take on projects in Battersea (1 mile), Fulham (1 mile), Notting Hill (2 miles), Shepherds Bush (3 miles).
East Molesey, in Surrey, is roughly 10 miles from Chelsea and also on our list. 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.
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Chelsea
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.
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.
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.
Are glass extensions cold in winter?
Modern double or triple glazing with warm-edge spacers and underfloor heating keeps them comfortable. They are not as warm as a solid room, and we explain the trade-off honestly.
How much does a glass extension cost?
Our guide range is about £3,900 to £7,540 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £54,500 to £69,000 in Chelsea.
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.