Double-storey extensions in Swansea

Covering Swansea

We work in Swansea (SA1) and the places around it, including Neath, Pontarddulais and Llanelli.

Homes in West Glamorgan

Welsh homes include long terraces built into hillsides, stone cottages and modern estates, and sloping sites often shape how and where an extension can go.

What does a double-storey extension involve?

A double-storey extension adds new rooms on both the ground and first floor in one build, typically a larger kitchen or living space downstairs and an extra bedroom or bathroom above. Because the roof and foundations are shared, the cost per square metre is usually lower than a single-storey extension.

Householder planning application
Foundations, steelwork, brick and block walls, roof
Joining the new first floor to the existing landing

What is the guide price for a double-storey extension in Swansea?

Guide prices for double-storey extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.

Double-storey extensions	Guide price incl. VAT
Standard specification	£2,400 to £2,900 per m²
Good specification	£2,900 to £3,400 per m²
High specification	£3,400 to £3,850 per m²

What approvals does a double-storey extension need in Wales?

In Wales the planning rules, including what counts as permitted development, are set by the Welsh Government, and Welsh building regulations differ in places from England’s. We check both against your house before drawings are finalised, and handle party wall notices where needed.

Most two-storey extensions in Wales need householder planning permission from the council. We prepare and submit the application and deal with any questions from the planning officer.

What can affect a double-storey extension?

Neighbours’ light is assessed using the 45-degree guide many councils use.
The first-floor link can mean moving a bathroom or reshaping the landing.

What are the steps?

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Double-storey extensions: common questions

Is a two-storey extension better value than a single-storey one?

Per square metre, usually yes, because the foundations and roof serve two floors of space.

Will we need to move out?

Most people stay. The noisiest stage is when we break through into the existing first floor, which we plan for a short window.

How do I get a price for double-storey extensions in Swansea?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Double-storey extensions near Swansea

Learn more about double-storey extensions, or see every project we cover in Swansea.