Single-storey rear extensions for homes in Swansea
From the first sketch to final sign-off, we plan and build single-storey extensions in Swansea and the surrounding West Glamorgan area.
- Guide price in SwanseaFrom £19,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time10–16 weeks on site
- Postcode districtsSA1, SA2, SA3, SA5, SA6
Is a single-storey extension right for your house?
- Semi-detached and detached houses with a usable rear garden
- Terraced houses that want a deeper kitchen across the full width
- Homeowners who want open-plan living onto the garden
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
The Party Wall etc. Act 1996 applies in Wales as in England: notice must be served before work to a shared wall, building on the boundary, or excavating close to a neighbour's foundations.
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).
Extensions in and around Swansea
Our survey diary covers Swansea, including SA1, SA2, SA3, SA5, SA6, SA7. We also work in nearby Clydach (5 miles), Briton Ferry (5 miles), Gorseinon (5 miles), Neath (7 miles).
Just over the Dyfed border, Llanelli is about 10 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 Swansea?
Labour and material costs vary across the UK, so for Swansea we use our Wales factor (×0.93). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Swansea: £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 |
For a figure based on your own dimensions, use our guide-price tool.
What happens next
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
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.
Single-storey extension questions answered
Will my neighbours in Swansea 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.
Do I need building regulations approval in Swansea?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Swansea?
Yes. We cover Swansea and the surrounding parts of West Glamorgan. Site visits are free and there is no obligation.
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 Swansea, plus design and council fees.
Will I need a steel beam?
Almost always. Opening up the rear wall to join the new room to the house needs a beam, usually steel, sized by a structural engineer. It is included in our quotes.
Book a free site visit in Swansea
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.