Carmarthen, West Wales
Two-storey rear extension in Carmarthen
Thinking about a two-storey rear extension in Carmarthen? A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
Carmarthen sits in West Wales, with postcode districts including SA31. In Carmarthen, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Carmarthen?
In Carmarthen, our guide for a two-storey rear extension is £1,670–£2,510 per square metre including VAT for a standard specification. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £50,000–£75,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £80,500–£120,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a two-storey rear extension in Carmarthen?
Whether your two-storey rear extension in Carmarthen needs a planning application depends on its size, your house and any local restrictions.
In Wales a rear extension of more than one storey can be permitted development if the ground floor projects no more than 4 metres and the upper floor no more than 3 metres, with at least 10.5 metres to the rear boundary. It is not permitted development in conservation areas, National Parks or National Landscapes, so many double-storey schemes need a householder application.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Carmarthen like to extend?
Older terraces near the centre and post-war semis further out are typical of Carmarthen. Sloping sites are common in Wales, so floor levels and retaining walls are designed at the start.
How a two-storey rear extension in Carmarthen comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Approvals
Permitted development check or householder planning application, then Building Regulations drawings to the Welsh Approved Documents and structural calculations, plus party wall notices where they apply.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Two-storey rear extensions near Carmarthen
From Carmarthen, the nearest places we also cover are Llanelli (13.5 miles) and Ammanford (14.2 miles).
- Two-storey rear extension in Llanelli
- Two-storey rear extension in Ammanford
- Two-storey rear extension in Gorseinon
- Two-storey rear extension in Clydach
- Two-storey rear extension in Swansea
Other work in Carmarthen:
FAQ
Two-storey rear extension questions in Carmarthen
Do I need planning permission for a rear extension in Carmarthen?
Often not for a single-storey rear extension of up to 4 metres under Welsh permitted development. Wales has no prior approval route for deeper extensions.
How long does a rear extension take to build in Carmarthen?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Does a two-storey rear extension need planning permission?
Almost always. England and Northern Ireland allow 3 metres without an application only if at least 7 metres remains to the rear boundary; Wales and Scotland are similar or stricter.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
Do I need a party wall agreement?
In Wales, usually yes if the extension is on or near a shared boundary or close to a neighbour's foundations. We serve the notices.