Pitched roof extensions across Chiswick
Thinking about a pitched roof extension for your Chiswick 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 ChiswickFrom £28,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsSW13, SW14, W3, W4, W6

Is a pitched roof extension right for your house?
- Conservation-sensitive streets
- Traditional, period and rural houses
- Homeowners who prefer a vaulted ceiling
Matching tiles is harder than it sounds. We source reclaimed or closest-match tiles where the originals are no longer made and agree samples with you before ordering.
Pitched roof extension prices in Chiswick
These guide figures apply our London adjustment (×1.3) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Chiswick: £2,400 to £4,550 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £28,500 – £34,000 | £33,500 – £43,000 | £42,500 – £55,000 |
| 4 m × 5 m 20 m² | £48,000 – £56,000 | £55,500 – £71,500 | £71,500 – £91,000 |
| 5 m × 6 m 30 m² | £72,000 – £84,000 | £83,500 – £107,500 | £107,000 – £136,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Working in Chiswick
Site visits are available across Chiswick (SW13, SW14, W3, W4, W6, W12). Nearby, we also take on projects in Acton (1 mile), Barnes (1 mile), Shepherds Bush (2 miles), Notting Hill (3 miles).
Across London, terraced houses with narrow side returns and tight access are the norm, which shapes everything from party wall notices to how materials reach the back garden.
Planning and approvals in Chiswick
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.
The planning position for a specific Chiswick address depends on its history and any designations, which is why we check it at the first visit.
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).
Our process, step by step
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 produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Chiswick
Who do I contract with for a pitched roof extension in Chiswick?
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 long does a pitched roof extension take to build in Chiswick?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Chiswick, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Can I have a vaulted ceiling?
Yes. A vaulted ceiling with roof windows is one of the main reasons to choose a pitched roof. It needs insulation between and under the rafters to meet the building regulations.
How much does a pitched roof extension cost?
Our guide range is about £2,400 to £4,550 per m² including VAT, a little more than a flat roof because of the roof structure and tiles.
Book a free site visit in Chiswick
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.