Single-storey rear extensions across Briton Ferry
A single-storey extension in Briton Ferry starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in Briton FerryFrom £19,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time10–16 weeks on site
- Postcode districtsSA12

Is a single-storey extension right for your house?
- Terraced houses that want a deeper kitchen across the full width
- Semi-detached and detached houses with a usable rear garden
- Homeowners who want open-plan living onto the garden
Depth is the big decision. Every extra metre adds floor area but also takes garden and can push you out of permitted development. We draw the room at two or three depths so you can see the trade-off in space, light and cost before anything is fixed.
Extensions in and around Briton Ferry
Site visits are available across Briton Ferry (SA12). Neighbouring towns we cover include Neath (2 miles), Clydach (5 miles), Swansea (5 miles), Gorseinon (10 miles).
Just over the Mid Glamorgan border, Maesteg is about 7 miles away. 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.
How much does a single-storey extension cost in Briton Ferry?
For Briton Ferry we adjust our national guide rates by ×0.93, the factor we use for Wales. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Briton Ferry: £1,630 to £3,160 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 – £38,000 |
| 4 m × 5 m 20 m² | £32,500 – £38,500 | £38,000 – £48,500 | £48,000 – £63,500 |
| 5 m × 6 m 30 m² | £48,500 – £57,500 | £57,000 – £73,000 | £72,500 – £95,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Do I need planning permission in Briton Ferry?
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.
The planning position for a specific Briton Ferry 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 before the foundations go in.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Single-storey extension questions answered
Will my neighbours in Briton Ferry be involved?
If a planning application is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Who do I contract with for a single-storey extension in Briton Ferry?
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 Briton Ferry, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Flat roof or pitched roof?
Flat roofs give more headroom inside and suit lanterns and rooflights; pitched roofs can blend better with older houses. Both meet building regulations when built properly. See our flat roof and pitched roof pages for the details.
How much does a single-storey extension cost per square metre?
Our guide range is about £1,630 to £3,160 per m² including VAT, depending on specification. A standard-spec 4 m × 5 m room usually lands at £38,000 to £48,500 in Briton Ferry, plus design and council fees.
Book a free site visit in Briton Ferry
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.