Carmarthen, West Wales
Glazed rear extension in Carmarthen
For homes in Carmarthen, a glazed rear extension is often the simplest way to gain space without moving. Full-height glass, slim frames and big rooflights for the most open rear room. We take it from survey to completion certificate.
Carmarthen and its postcode districts SA31 are part of our West Wales coverage. Glass-led rear extensions in Carmarthen are planned around which way the garden faces, because that decides the glass specification.
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 glazed rear extension cost in Carmarthen?
In Carmarthen, our guide for a glazed rear extension is £2,600–£4,460 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 wide × 4 m deep (12 m²) | £31,000–£53,500 |
| 4 m wide × 6 m deep (24 m²) | £62,500–£107,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a glazed rear extension in Carmarthen?
Here is how the rules in Wales apply to a glazed rear extension in Carmarthen.
In Wales a single-storey rear extension can often be permitted development if it projects no more than 4 metres beyond the rear wall and is no more than 4 metres high. Wales has no prior approval route for deeper extensions, so anything bigger needs a householder planning application.
Wales has its own Approved Document L, with targets for walls, roofs, floors and glazing similar to but not identical with England's. Heavily glazed designs are checked with a calculation.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
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 glazed rear extension in Carmarthen comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
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.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Glazed rear extensions near Carmarthen
We also build glazed and glass-box rear extensions in nearby Llanelli (13.5 miles) and Ammanford (14.2 miles).
- Glazed rear extension in Llanelli
- Glazed rear extension in Ammanford
- Glazed rear extension in Gorseinon
- Glazed rear extension in Clydach
- Glazed rear extension in Swansea
Other work in Carmarthen:
FAQ
Glazed rear extension questions in Carmarthen
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.
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.
Will a glass extension be too hot?
Not if it is designed for its orientation, with solar-control glass, shading and ventilation.
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.
How much does a glazed rear extension cost in Carmarthen?
As a guide, £2,600–£4,460 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £31,000–£53,500 at that rate. Your written price follows the survey.
Do you handle building control in Carmarthen?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.