Double-storey extensions in Dyfed

Covering Dyfed

Our coverage across Dyfed includes Llanelli, Ammanford, Aberystwyth and Carmarthen.

Homes in Dyfed

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 is a double-storey extension?

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.

Measured survey, design and planning drawings
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 Dyfed?

Typical ranges for double-storey extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.

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 change the price or programme?

Side extensions close to a boundary are often set back or stepped down so they do not create a terraced effect.
The new roof is tied into the old one, so roof tiles and ridge details need to match.

What happens after I enquire?

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

What people ask before starting

How much does a two-storey extension cost?

Typically about £2,400 to £3,850 per square metre of new floor area including VAT. A 40 m² extension across two floors is often around £100,000 to £150,000 depending on specification.

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.

Do you work in Dyfed?

Yes. Dyfed is within our coverage for double-storey extensions, along with nearby Llanelli and Ammanford.

Double-storey extensions in nearby towns

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