Covering Whitchurch, South Glamorgan
Alongside Whitchurch, South Glamorgan, we also cover Cardiff, Caerphilly (4 miles to the north) and Penarth.
Homes in South 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 goes into a single-storey extension?
A single-storey extension adds one level of new floor space to the back or side of a house, usually to open up a kitchen, dining or family room. It is the most common way to gain space without moving, and many can be built without a planning application.
- Building control application and inspections
- Foundations, drainage and structural steel
- Brickwork, roof, glazing and insulation
How much does a single-storey extension cost in Whitchurch, South Glamorgan?
Guide prices for single-storey extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.
| 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 |
How is a single-storey extension approved in Whitchurch, South Glamorgan?
Welsh projects need planning clearance from the council under Welsh rules, building regulations approval under the Welsh approved documents, and party wall notices where the work affects a neighbour’s wall or foundations.
Wales has its own permitted development rules, set by the Welsh Government. Small single-storey rear extensions can often go ahead without an application, but the limits differ from England's and there is no larger-extension prior approval route, so we check the current Welsh rules for your house before drawings are finalised.
What can change the price or programme?
- Drains under the footprint may need diverting or a build-over agreement with the water company.
- Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.
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.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
Single-storey extensions: common questions
How much does a single-storey extension cost?
Most single-storey extensions cost about £2,600 to £4,000 per square metre including VAT, depending on specification, glazing and ground conditions. We give a fixed price in writing for the agreed specification after the survey.
Do you need to dig up the drains?
Sometimes. If a public sewer runs under the extension, the water company has to agree a build-over or a diversion. We check this at survey stage.
Can you visit a house in Whitchurch, South Glamorgan 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.
Other towns nearby
- Single-storey extensions in Cardiff
- Single-storey extensions in Caerphilly
- Single-storey extensions in Penarth
- Single-storey extensions in Pontypridd
Learn more about single-storey extensions, or see every project we cover in Whitchurch.

