Bedroom extensions across Carmarthen
A bedroom extension in Carmarthen 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 CarmarthenFrom £24,000 inc VAT
- PlanningUsually a planning application
- Build time14–22 weeks on site
- Postcode districtsSA31
Extensions in and around Carmarthen
Postcode districts we cover around Carmarthen include SA31. Neighbouring towns we cover include Llanelli (13 miles), Ammanford (14 miles), Haverfordwest (29 miles), Pembroke Dock (29 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.
Bedroom extension prices in Carmarthen
Prices below are for Carmarthen, using the Wales factor of ×0.93. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Carmarthen: £1,490 to £2,980 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £24,000 – £29,500 | £24,000 – £31,500 | £26,500 – £36,000 |
| Bedroom and en-suite 18 m² | £26,500 – £33,000 | £31,500 – £41,500 | £40,000 – £54,000 |
| Two rooms 30 m² | £44,500 – £54,500 | £53,000 – £68,500 | £66,500 – £89,500 |
For a figure based on your own dimensions, use our guide-price tool.
Will the council need to approve it?
In Wales a rear extension of more than one storey can be permitted development only if the ground floor projects no more than 4 m, the upper floor no more than 3 m, it stays at least 10.5 m from the rear boundary and it is not in a conservation area, national park, National Landscape or World Heritage Site. Anything larger needs a planning application to the council.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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).
What is included
- Fire safety: escape windows and smoke alarms to building regulations
- Planning drawings and application
- Layout options: two-storey, over-garage or ground floor
- En-suite drainage and ventilation design
- Structure, roof, insulation and finish
New bedrooms on an upper floor need an escape window or a protected route to the outside under the building regulations. We design the window sizes and stair route to meet that from the outset.
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Common questions in Carmarthen
Who do I contract with for a bedroom extension in Carmarthen?
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 Carmarthen, 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 I need building regulations approval in Carmarthen?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will a new bedroom need planning permission?
Upstairs additions usually do. Ground-floor rooms may fall within permitted development, depending on size and position.
How much does a bedroom extension cost?
Our guide range is about £1,490 to £2,980 per m² including VAT. A bedroom with an en-suite of about 18 m² is typically £31,500 to £41,500 at standard spec, depending on whether it is part of a larger two-storey build.
Book a free site visit in Carmarthen
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.