Flat roof extensions for homes in Ossett
From the first sketch to final sign-off, we plan and build flat roof extensions in Ossett and the surrounding West Yorkshire area.
- Guide price in OssettFrom £19,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsWF5, WF12

Local to Ossett
Our survey diary covers Ossett, including WF5, WF12. The same team covers Dewsbury (2 miles), Batley (3 miles), Wakefield (3 miles), Morley (4 miles), all within easy reach.
For homes towards South Yorkshire, Darton is around 7 miles away. Yorkshire and the Humber combines stone-built terraces in the Pennine towns with brick semis and newer estates elsewhere, so materials and roof details need matching with care.
Who a flat roof extension suits
- Extensions under first-floor windows where a pitch will not fit
- Modern and 1930s onwards houses
- Homeowners who want maximum light from above
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.
Flat roof extension prices in Ossett
Prices below are for Ossett, using the Yorkshire and the Humber factor of ×0.94. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Ossett: £1,640 to £3,150 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,500 – £23,500 | £23,000 – £29,500 | £29,000 – £38,000 |
| 4 m × 5 m 20 m² | £32,500 – £39,000 | £38,500 – £49,000 | £48,500 – £63,000 |
| 5 m × 6 m 30 m² | £49,000 – £58,000 | £57,500 – £73,500 | £73,000 – £94,500 |
For a figure based on your own dimensions, use our guide-price tool.
Do I need planning permission in Ossett?
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
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
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Your questions about a flat roof extension in Ossett
Do you cover all of Ossett?
Yes. We cover Ossett and the surrounding parts of West Yorkshire. Site visits are free and there is no obligation.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Ossett, 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 Ossett?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
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.
Are flat roof extensions cheaper?
Usually slightly, because there is less roof structure and no tiles. Our guide range is about £1,640 to £3,150 per m² including VAT.
Book a free site visit in Ossett
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.