Colwyn Bay, North Wales
Single-storey rear extension in Colwyn Bay
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. We design, get the approvals for and build single-storey rear extensions in Colwyn Bay and the surrounding area, with one contract from the first survey to building control sign-off.
Colwyn Bay and its postcode districts LL28, LL29 and LL31 are part of our North Wales coverage. On older terraces and post-war semis like those around Colwyn Bay, a single-storey rear extension is usually the simplest way to fix a small back kitchen without touching the bedrooms.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a single-storey rear extension cost in Colwyn Bay?
Guide prices for a single-storey rear extension in Colwyn Bay start from our Wales rate of £1,770–£2,880 per square metre, including VAT. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,000–£34,500 |
| 4 m wide × 5 m deep (20 m²) | £35,500–£57,500 |
| 4 m wide × 6 m deep (24 m²) | £42,500–£69,000 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a single-storey rear extension in Colwyn Bay?
The planning route for a single-storey rear extension in Colwyn Bay is set by Wales's householder rules and your council.
Welsh permitted development allows a single-storey rear extension of up to 4 metres in depth and 4 metres in height, subject to boundary and garden-coverage limits. There is no larger-extension prior approval scheme in Wales.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Colwyn Bay like to extend?
Older terraces near the centre and post-war semis further out are typical of Colwyn Bay. Sloping sites are common in Wales, so floor levels and retaining walls are designed at the start.
How a single-storey rear extension in Colwyn Bay comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Paperwork handled
Planning or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Single-storey rear extensions near Colwyn Bay
Neighbouring places we cover include Llandudno (4.8 miles) and Abergele (6.0 miles).
- Single-storey rear extension in Llandudno
- Single-storey rear extension in Abergele
- Single-storey rear extension in Rhyl
- Single-storey rear extension in Prestatyn
- Single-storey rear extension in Bangor
Other work in Colwyn Bay:
FAQ
Single-storey rear extension questions in Colwyn Bay
Do you handle building control in Colwyn Bay?
Yes. We apply to the council or a registered approver under the Welsh regulations and hand over the completion certificate.
How long does a rear extension take to build in Colwyn Bay?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Does it add value to the house?
Nationwide's October 2025 house price research found that a 10% increase in floor area is linked to about 5% higher value on average. It is a guide, not a promise; local agents can tell you what extended homes on your street sell for.
Do I need a party wall agreement?
In Wales, usually yes if the extension is on or near a shared boundary or close to a neighbour's foundations. We serve the notices.
Can you match the brick or stone on my Colwyn Bay house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do I need planning permission for a rear extension in Colwyn Bay?
Often not for a single-storey rear extension of up to 4 metres under Welsh permitted development. Wales has no prior approval route for deeper extensions.