West Wales
Rear extensions for semi-detached houses in West Wales
Single or two-storey extensions for semi-detached houses, with side access and one party wall. Across West Wales we handle the whole rear extension: survey, drawings, the planning route, building control and the build. Towns we cover here include Llanelli, Aberystwyth and Carmarthen.
Semi-detached houses are common across West Wales, and their side access makes rear extensions quicker to build. Older terraces near the centre and post-war semis further out are typical of West Wales. Sloping sites are common in Wales, so floor levels and retaining walls are designed at the start.
How much does a semi-detached rear extension cost in West Wales?
A semi-detached rear extension in West Wales is priced at £1,770–£2,880 per square metre including VAT as a guide, before kitchen fit-out and fees. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,000–£34,500 |
| 4 m wide × 5 m deep (20 m²) | £35,500–£57,500 |
| 4 m wide × 6 m deep (24 m²) | £42,500–£69,000 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission in West Wales?
The Welsh Government's householder rules let many homes add a single-storey rear extension up to 4 metres deep and 4 metres high without a planning application. Deeper projects go through a householder application, because Wales has no prior approval route.
Welsh rules allow a two-storey rear extension without an application only where the ground floor is no deeper than 4 metres, the upper floor no deeper than 3 metres and at least 10.5 metres remains to the rear boundary. Most homeowners still apply for householder planning permission.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent.
Where in West Wales do we work?
FAQ
Questions people ask
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
Single or two-storey on a semi?
Two-storey if you need bedrooms, single-storey if you need a bigger kitchen. Planning risk is lower for single-storey.
What if my neighbour has already extended?
That can make a matching depth easier to justify. We measure theirs at the survey.
Do you cover all of West Wales?
We cover 6 towns and districts in West Wales, including Llanelli, Aberystwyth and Carmarthen.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.