Covering Merthyr Tydfil
Merthyr Tydfil is about 19 miles north-east of Bridgend. We also cover Aberdare (4 miles to the south-west), Rhondda and Ebbw Vale.
Homes in Mid 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 does a single-storey extension involve?
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.
- Foundations, drainage and structural steel
- Brickwork, roof, glazing and insulation
- First-fix and second-fix electrics, plastering and making good
What will a single-storey extension cost?
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 |
What approvals does a single-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.
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 affect a single-storey extension?
- 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.
What are the steps?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- 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.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
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.
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 Merthyr Tydfil 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 Aberdare
- Single-storey extensions in Rhondda
- Single-storey extensions in Ebbw Vale
- Single-storey extensions in Tonypandy
Learn more about single-storey extensions, or see every project we cover in Merthyr Tydfil.

