Two-storey extensions for detached houses in Llanelli
Our two-storey extensions for detached houses service in Llanelli covers everything: measured survey, design, planning or permitted development checks, structural design, building control and the build itself.
Useful details for planning a two-storey extension for a detached house in Llanelli.
- Postcode districts
- SA15
- County / area
- Dyfed, Wales
- Price region
- Wales
- Guide price
- £79,000–£106,500 (£1,890–£2,530 per m²)
- Approval route
- Depends on position: rear (3 m first floor, 10.5 m to the boundary) and some side extensions (10.5 m, 1 m set-back) can be permitted development in Wales.
- Nearest towns
- Burry Port (3.6 miles), Gorseinon (5.2 miles), Pontarddulais (5.7 miles)
- First visit
- Free, no obligation
About a two-storey extension for a detached house
A two-storey extension for a detached house is a two-floor addition to the side, rear or both of a house that stands on its own plot. Detached houses often have room on more than one side, so there is more choice of layout and fewer shared-wall issues. The design still needs to respect boundaries, neighbours' windows and the look of the house.
We cover Llanelli (SA15) and the places around it, including Burry Port (3.6 miles), Gorseinon (5.2 miles) and Pontarddulais.
What it costs in Llanelli
A guide price for Llanelli: around £79,000–£106,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). That works out at £1,890–£2,530 per m² of new floor space, including VAT at 20%. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.
| Spec | Per m² | A 3 m × 7 m footprint on two floors (42 m² of new floor space) |
|---|---|---|
| Essential | £1,740–£2,330 per m² | £73,000–£98,000 |
| Standard | £1,890–£2,530 per m² | £79,000–£106,500 |
| Premium | £2,260–£3,040 per m² | £95,000–£127,500 |
Planning and building regulations in Llanelli
In Wales, detached houses are more likely to meet the permitted development tests for a two-storey side extension: 10.5 m to the boundary opposite the side wall, a 1 m set-back from the front and no more than 50% added width. Rear permitted development allows 4 m on the ground floor and 3 m on the first floor. Otherwise the fee is £585.
Approval in Wales: Householder planning application: £585. Councils normally decide householder applications within 8 weeks.
Building regulations: Building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency).
Design points for Llanelli homes
Choosing the best side
On a detached house you can often extend on either side or the rear. We look at orientation for daylight, where the stairs and landing are, the distance to each boundary, drains and trees, so the extension goes where it adds the most useful space.
Larger spans and steelwork
Bigger extensions often mean wider openings and longer spans, which need more steel and sometimes a steel frame. The engineer designs these early, because the size of the steel affects ceiling heights, floor depths and the cost.
How we'd run your project
Measure and listen
A visit to Llanelli to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Get it approved
Once you're happy with the design we submit it to the council for Llanelli and deal with any questions from the planning officer.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Questions about two-storey extensions for detached houses in Llanelli
Do I need planning permission for a two-storey extension for a detached house in Llanelli?
Llanelli is in Wales, so Wales planning rules apply. Depends on position: rear (3 m first floor, 10.5 m to the boundary) and some side extensions (10.5 m, 1 m set-back) can be permitted development in Wales. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
How much does a two-storey extension for a detached house cost in Llanelli?
Our guide for Wales, which covers Llanelli, is £1,890–£2,530 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £79,000–£106,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Which postcodes do you cover around Llanelli?
We cover Llanelli (SA15) and nearby places including Burry Port, Gorseinon and Pontarddulais, plus the rest of Dyfed. The first site visit is free.
Can I extend a detached house on both sides?
Sometimes. With planning permission, a council may accept extensions on both sides if the house stays well proportioned and keeps gaps to the boundaries. It is more common to extend on one side and the rear, or with a wraparound. We look at the plot as a whole before suggesting more than one extension.
Is a detached house extension a better investment than moving?
It often costs less than the gap between your house and a larger one nearby, once property tax, legal fees and removal costs are counted, but that depends on your area. Extending also has limits: every street has a ceiling price. We give you build costs so you can compare them with local asking prices.
Nearby
Close to Llanelli? We work across the area, including:
Other extensions in Llanelli
- Rear
- Side
- Wraparound
- Part two-storey
- Over a garage
- First floor
- Semi-detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Llanelli · Two-storey extensions for detached houses across Dyfed
Book a free site visit in Llanelli and we'll tell you what's possible, what approvals you need and what the design stage would cost.