Colwyn Bay, North Wales
Semi-detached rear extension in Colwyn Bay
We plan and build rear extensions for semi-detached houses for homeowners in Colwyn Bay. Single or two-storey extensions for semi-detached houses, with side access and one party wall. Start with a free site visit, then a written price once the design is agreed.
Colwyn Bay sits in North Wales, with postcode districts including LL28, LL29 and LL31. In Colwyn Bay we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours.
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 semi-detached rear extension cost in Colwyn Bay?
In Colwyn Bay, our guide for a semi-detached rear extension is £1,770–£2,880 per square metre including VAT for a standard specification. 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 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a semi-detached rear extension in Colwyn Bay?
Here is how the rules in Wales apply to a semi-detached rear extension in Colwyn Bay.
The Welsh Government's householder rules let many homes add a single-storey rear extension up to 4 metres deep and 4 metres high without a planning application. Deeper projects go through a householder application, because Wales has no prior approval route.
Welsh rules allow a two-storey rear extension without an application only where the ground floor is no deeper than 4 metres, the upper floor no deeper than 3 metres and at least 10.5 metres remains to the rear boundary. Most homeowners still apply for householder planning permission.
Conservation areas, National Parks and National Landscapes restrict permitted development in Wales, and listed buildings need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
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 semi-detached rear extension in Colwyn Bay comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Paperwork handled
Planning or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Semi-detached rear extensions near Colwyn Bay
Close by, we work in Llandudno, about 4.8 miles away, and Abergele, about 6.0 miles away.
- Semi-detached rear extension in Llandudno
- Semi-detached rear extension in Abergele
- Semi-detached rear extension in Rhyl
- Semi-detached rear extension in Prestatyn
- Semi-detached rear extension in Bangor
Other work in Colwyn Bay:
FAQ
Semi-detached rear extension questions in Colwyn Bay
Is the site visit in Colwyn Bay free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
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.
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
What postcode areas do you cover around Colwyn Bay?
Including LL28, LL29 and LL31, and the surrounding North Wales area.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.