Gorseinon flat roof extensions, designed and built
Gorseinon homeowners can use us for the whole flat roof extension project: survey, design, planning or permitted development checks, building regulations and the build itself.
- Guide price in GorseinonFrom £19,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time10–16 weeks on site
- Postcode districtsSA4
Will the council need to approve it?
In Wales a single-storey rear extension can usually project up to 4 m beyond the rear wall without a planning application, if it is no more than 4 m high, keeps eaves to 3 m and overall height to 4 m within 2 m of a boundary, and covers no more than half the land around the original house. Wales has no larger home extension prior approval scheme.
In a conservation area, national park, National Landscape or 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 before the foundations go in.
Building regulations approval is separate from planning. Wales has its own building regulations and approved documents; the council or a registered building control approver checks the plans, inspects the work and issues a completion certificate.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
What is included
- Parapets or edge trims and flashings to the house
- Membrane choice: single-ply, EPDM or GRP
- Lanterns or rooflights with upstands
- Falls and outlets designed to drain properly
Guide prices for Gorseinon
Prices below are for Gorseinon, using the Wales factor of ×0.93. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Gorseinon: £1,630 to £3,120 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £19,500 – £23,000 | £22,500 – £29,500 | £29,000 – £37,500 |
| 4 m × 5 m 20 m² | £32,500 – £38,500 | £38,000 – £48,500 | £48,000 – £62,500 |
| 5 m × 6 m 30 m² | £48,500 – £57,500 | £57,000 – £73,000 | £72,500 – £93,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Covering Gorseinon
Postcode districts we cover around Gorseinon include SA4. Neighbouring towns we cover include Swansea (5 miles), Clydach (6 miles), Briton Ferry (10 miles), Neath (10 miles).
Welsh housing ranges from stone terraces in the valleys to render-and-slate houses and modern estates, and the Welsh planning rules differ from England's in several places.
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 Gorseinon home, measure up, talk through what you want and check the planning position.
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
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions people ask about flat roof extensions
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Gorseinon, 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 Gorseinon?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Do I need building regulations approval in Gorseinon?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Are flat roof extensions cheaper?
Usually slightly, because there is less roof structure and no tiles. Our guide range is about £1,630 to £3,120 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 Gorseinon
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.