Flat roof extensions in Birmingham: design, approvals and build
If you live in Birmingham and want more space without moving, a flat roof extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in BirminghamFrom £20,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsB1, B2, B3, B4, B5
Local to Birmingham
Across B1, B2, B3, B4, B5, B19, we can visit, measure and advise. Nearby, we also take on projects in Smethwick (3 miles), West Bromwich (5 miles), Shirley (6 miles), Halesowen (7 miles).
Bromsgrove, in Worcestershire, is roughly 12 miles from Birmingham and also on our list. The West Midlands has a large stock of 1930s and post-war semi-detached houses, which are well suited to rear, side and over-garage extensions, plus Victorian terraces in the older inner areas.
What should I budget for a flat roof extension in Birmingham?
For Birmingham we adjust our national guide rates by ×0.97, the factor we use for West Midlands. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Birmingham: £1,700 to £3,250 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £20,000 – £24,000 | £23,500 – £30,500 | £30,000 – £39,000 |
| 4 m × 5 m 20 m² | £33,500 – £40,000 | £39,500 – £50,500 | £50,000 – £65,000 |
| 5 m × 6 m 30 m² | £50,500 – £60,000 | £59,500 – £76,000 | £75,500 – £97,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Do I need planning permission in Birmingham?
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.
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.
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.
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).
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
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
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about flat roof extensions
Who do I contract with for a flat roof extension in Birmingham?
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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Birmingham, 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 you cover all of Birmingham?
Yes. We cover Birmingham and the surrounding parts of West Midlands. Site visits are free and there is no obligation.
Are flat roof extensions cheaper?
Usually slightly, because there is less roof structure and no tiles. Our guide range is about £1,700 to £3,250 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 Birmingham
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.