Single-storey rear extensions across Cwmbran
A single-storey extension in Cwmbran 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 CwmbranFrom £19,500 inc VAT
- PlanningWelsh permitted development rules (rear up to 4 m)
- Build time10–16 weeks on site
- Postcode districtsNP44
Do I need planning permission in Cwmbran?
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 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.
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.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Local to Cwmbran
Site visits are available across Cwmbran (NP44). We also work in nearby Pontypool (3 miles), Newport, Gwent (5 miles), Ebbw Vale (12 miles), Abergavenny (12 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.
Single-storey extension prices in Cwmbran
For Cwmbran 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 Cwmbran: £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.
Included in a typical project
- Measured survey and design
- Foundations, drainage and groundworks
- Building regulations drawings and structural calculations
- Walls, steel beams and the new opening into the house
- Doors, windows, insulation, plastering and first fix to finish
- Flat or pitched roof, rooflights or lantern
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 Cwmbran 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
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.
Common questions in Cwmbran
Who do I contract with for a single-storey extension in Cwmbran?
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.
Do you cover all of Cwmbran?
Yes. We cover Cwmbran and the surrounding parts of Gwent. 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 Cwmbran, 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 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 Cwmbran, plus design and council fees.
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.
Book a free site visit in Cwmbran
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.