Extensions in Llanelli: design, planning and build
We design and build house extensions for homes in Llanelli and the surrounding Dyfed area, with guide prices adjusted for the region.
- Postcode districtsSA15
- Price regionWales (×0.93)
- Planning rulesWales
- Site visitFree, no obligation
What works best for Llanelli houses?
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.
Depending on the plot, side return extensions and bungalow extensions are often the strongest options, with pitched roof extensions worth considering where there is room.
Covering Llanelli and nearby
We cover Llanelli and the postcode districts SA15. We also work in nearby Ammanford (11 miles), Carmarthen (13 miles), Pembroke Dock (33 miles), Haverfordwest (36 miles), Aberystwyth (51 miles). For homes towards West Glamorgan, Gorseinon is around 5 miles away.
Approvals for an extension in Llanelli
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 Wales a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house, and it must not come closer to a highway than the existing side wall. Larger side extensions need planning permission.
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.
Applications are decided by the local planning authority (your county or county borough council, or the national park authority).
Popular extension prices in Llanelli
Every figure below is a guide for Llanelli, adjusted for Wales build costs (×0.93) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Wraparound extensions | 25 m² | £53,000 – £67,500 |
| Double-storey extensions | 32 m² | £53,500 – £70,000 |
| Single-storey rear extensions | 20 m² | £38,000 – £48,500 |
| Conservatory replacement extensions | 14 m² | £27,500 – £36,000 |
| Side return extensions | 11 m² | £24,500 – £31,000 |
Extension types and starting prices
- Single-storey rear extensions · from £19,500
- Bedroom extensions · from £24,000
- Extension plans and drawings · from £1,100
- Building regulations for extensions · from £800
- Orangery extensions · from £27,500
- Annexe extensions · from £51,000
- Flat roof extensions · from £19,500
- Kitchen extensions · from £25,000
- Porch extensions · from £3,700
- Home office extensions · from £14,500
- Side extensions · from £20,000
- Conservatory replacement extensions · from £18,500
- Double-storey extensions · from £35,000
- Utility and boot room extensions · from £13,000
- Pitched roof extensions · from £20,500
- Glass box extensions · from £27,500
- Wraparound extensions · from £33,000
- Planning permission for extensions · from £300
- Extensions over a garage · from £22,000
- Bungalow extensions · from £24,000
- Side return extensions · from £16,500
- Timber frame extensions · from £19,500
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions about extensions in Llanelli
How much does an extension cost in Llanelli?
Using our Wales factor (×0.93), a standard-spec single-storey extension of 20 m² is a guide £38,000 to £48,500 including VAT, and a 32 m² two-storey extension £53,500 to £70,000. Your written price follows the survey.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Will my neighbours need to be told?
If you apply for planning the council notifies them, and in Wales party wall notices may be needed for work near a shared boundary.
Do you cover all of Llanelli?
Yes, including the surrounding parts of Dyfed. Site visits are free and there is no obligation.
Book a free site visit in Llanelli
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.