Two-storey side extensions in Swansea and Neath Port Talbot

Swansea and Neath Port Talbot at a glance

Nation: Wales
Price region: Wales
Postcode areas: SA
Towns covered: 9 listed below, plus surrounding villages
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.
Site visits: Free, no obligation

What a two-storey side extension involves

A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.

Swansea and Neath Port Talbot towns we list: Swansea (SA1), Neath (SA10), Briton Ferry (SA12), Gorseinon (SA4), Clydach (SA6) and Ystalyfera (SA9). Every other address in Swansea and Neath Port Talbot is covered as well.

Guide price in Wales

For budgeting in Swansea and Neath Port Talbot, allow around £79,000–£106,500 for a two-storey side extension with a 3 m × 7 m footprint on two floors (42 m² of new floor space). That's based on £1,890–£2,530 per m² including VAT for Wales. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	Typical project
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

Rules in Wales

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).

The Party Wall etc. Act 1996 applies in Wales, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

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 work in Swansea and Neath Port Talbot

Visit and first ideas
One of our team visits your house in Swansea and Neath Port Talbot, checks the walls, roof and drains, and sketches out options with you.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Swansea and Neath Port Talbot.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Towns we cover in Swansea and Neath Port Talbot

Two-storey side extensions in Swansea and Neath Port Talbot: questions

How much does a two-storey side extension cost in Swansea and Neath Port Talbot?

In Wales our guide is £1,890–£2,530 per m² including VAT, so about £79,000–£106,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Essential and Premium specs move that by roughly 8% down or 20% up.

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.

Will I need planning permission in Swansea and Neath Port Talbot?

Swansea and Neath Port Talbot is in Wales. 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.

Neighbouring areas

All extension services in Swansea and Neath Port Talbot · About two-storey side extensions