Single-storey extensions in Cardiff

Covering Cardiff

Our coverage around Cardiff (CF10, CF11, CF14) also includes Whitchurch, Penarth and Caerphilly.

Homes in South Glamorgan

Housing in Wales ranges from terraced streets in the valleys and older industrial towns to stone-built homes in rural areas and modern estates around the cities.

What is a single-storey extension?

We design the extension around how you use the house: where the light comes from, how the new room joins the old one, and what happens to the drains and the garden. The structure is built in brick or block to match the house, finished with a flat roof and lantern or a pitched roof, then insulated, plastered and handed back ready to decorate.

Measured survey and design drawings
Building control application and inspections
Brickwork, roof, glazing and insulation

How much does a single-storey extension cost in Cardiff?

Use these ranges to budget for single-storey extensions; the survey turns them into a fixed price for the agreed specification.

Single-storey extensions	Guide price incl. VAT
Standard specification	£2,600 to £3,000 per m²
Good specification	£3,000 to £3,500 per m²
High specification	£3,500 to £4,000 per m²

Planning and building rules in Cardiff

Planning decisions in Wales are made by the local council, using permitted development rules set by the Welsh Government rather than England’s. Building regulations in Wales have their own approved documents, and the Party Wall etc. Act 1996 applies to work on shared walls and boundaries.

Wales has its own permitted development rules, set by the Welsh Government.

What should I think about before starting?

Drains under the footprint may need diverting or a build-over agreement with the water company.
Kitchens and doors have long lead times, so we order them early.

How does the project run?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
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 long does a single-storey extension take to build?

The build itself usually takes 10 to 16 weeks once work starts on site. Design, approvals and ordering usually add 6 to 12 weeks before that.

Will the brick match?

We source the closest available match for colour, size and texture and agree a sample panel with you before laying.

Can you visit a house in Cardiff to quote?

Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.

Single-storey extensions in nearby towns

Learn more about single-storey extensions, or see every project we cover in Cardiff.