Flat roof extensions for homes in Feltham
We design and build flat roof extensions for houses in Feltham, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in FelthamFrom £27,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsTW3, TW4, TW6, TW12, TW13
Working in Feltham
Across TW3, TW4, TW6, TW12, TW13, TW14, we can visit, measure and advise. Nearby, we also take on projects in Hanworth (2 miles), Hounslow (3 miles), Hampton (3 miles), Heston (3 miles).
For homes towards Surrey, Ashford, Surrey is around 2 miles away. 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.
How much does a flat roof extension cost in Feltham?
For Feltham 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 Feltham: £2,280 to £4,360 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £27,000 – £32,000 | £31,500 – £41,000 | £40,500 – £52,500 |
| 4 m × 5 m 20 m² | £45,500 – £53,500 | £53,000 – £68,000 | £67,500 – £87,500 |
| 5 m × 6 m 30 m² | £68,000 – £80,000 | £79,500 – £101,500 | £101,000 – £131,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Planning rules that apply in Feltham
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 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.
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 flat roof extension suits
- Homeowners who want maximum light from above
- Extensions under first-floor windows where a pitch will not fit
- Modern and 1930s onwards houses
Height is often what decides a flat roof. Under first-floor windows, a pitched roof may not fit at all; a flat roof keeps the extension low while still giving a good ceiling height inside.
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
We visit your Feltham home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Your questions about a flat roof extension in Feltham
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Feltham, 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 flat roof extension take to build in Feltham?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Will my neighbours in Feltham be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Are flat roof extensions cheaper?
Usually slightly, because there is less roof structure and no tiles. Our guide range is about £2,280 to £4,360 per m² including VAT.
Can I walk on a flat roof extension?
Only for maintenance unless it is designed as a terrace. A roof terrace or balcony needs planning permission and a different structure.
Book a free site visit in Feltham
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.