Covering Colwyn Bay
We work in Colwyn Bay (LL29) and the places around it, including Rhyl, Bangor and Llangefni.
Homes in Clwyd
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 single-storey extension involve?
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.
- Planning and building regulations checks under Welsh rules
- Building control application and inspections
- First-fix and second-fix electrics, plastering and making good
How much does a single-storey extension cost in Colwyn Bay?
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 Colwyn Bay?
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 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.
From first call to completion
- 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.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Your questions answered
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.
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.
Can you visit a house in Colwyn Bay 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
- Single-storey extensions in Rhyl
- Single-storey extensions in Bangor
- Single-storey extensions in Llangefni
- Single-storey extensions in Flint
Learn more about single-storey extensions, or see every project we cover in Colwyn Bay.

