Two-storey side extensions in Carmarthen

Useful details for planning a two-storey side extension in Carmarthen.

Postcode districts: SA31, SA32 and SA33
County / area: Dyfed, Wales
Price region: Wales
Guide price: £79,000–£106,500 (£1,890–£2,530 per m²)
Approval route: Can be permitted development in Wales if it is 10.5 m from the side boundary, set back 1 m from the front and doesn't widen the house by more than half; otherwise planning permission.
Nearest towns: Tumble (9.7 miles), Cross Hands (10.3 miles), Burry Port (12.1 miles)
Distance to Llanelli: about 13.5 miles
First visit: Free, no obligation

About a two-storey side extension

A two-storey side extension suits a detached or semi-detached house with a side garden, driveway or garage wide enough to build on. You get a design that sits comfortably on the street, a planning application or permitted development check depending on your nation, structural design, building regulations approval and the build itself. We manage the whole process, and the work is carried out by vetted teams working under S&K.

Around Carmarthen we also work in Tumble, Cross Hands and Burry Port, and across the rest of Dyfed. Postcode districts in and near Carmarthen: SA31, SA32 and SA33.

What it costs in Carmarthen

Guide prices for two-storey side extensions in Wales are around £1,890–£2,530 per m² of new floor space, including VAT. For a typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space), that's roughly £79,000–£106,500. Professional fees for drawings and the structural engineer are listed separately on our prices page.

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 Carmarthen

In Wales, a two-storey side extension can be permitted development if it is at least 10.5 m from the boundary opposite the side wall, set back at least 1 m from the front of the house and does not increase the house's widest width by more than 50%. If it fails any test, or the house is in a protected area, a householder application costs £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 Carmarthen homes

Access and services

Side extensions often cover the only route to the back garden, a gas meter, soil pipes or a drain run. We plan bin and bike access, move meters and pipes where needed and check drains early, because these items affect both cost and layout.

Avoiding a terracing effect

Where semi-detached houses sit close together, side extensions on neighbouring houses can join up and turn a row of pairs into a terrace. Many councils ask for a gap to the boundary at first floor to stop this, so we check local guidance before fixing the width.

How we'd run your project

Start at your house
We come to your home in Carmarthen, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about two-storey side extensions in Carmarthen

Which postcodes do you cover around Carmarthen?

We cover Carmarthen (SA31, SA32 and SA33) and nearby places including Tumble, Cross Hands and Burry Port, plus the rest of Dyfed. The first site visit is free.

How long does a two-storey side extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils normally decide householder applications within 8 weeks), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

Who handles building regulations for a project in Carmarthen?

We handle it as part of the project. What's needed in Wales: building regulations approval under the Welsh Approved Documents, which differ from England's in places (notably energy efficiency). We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

How much does a two-storey side extension cost in Carmarthen?

Our guide for Wales, which covers Carmarthen, 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.

Can I build a two-storey side extension over my driveway?

Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.

Nearby

We also cover places near Carmarthen, including:

Other extensions in Carmarthen

All two-storey extension services in Carmarthen · Two-storey side extensions across Dyfed

Want a figure first? Try our guide price tool, then book a free visit to firm it up.