Colwyn Bay, North Wales
Two-storey rear extension in Colwyn Bay
A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. We design, get the approvals for and build two-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. In Colwyn Bay, a two-storey rear extension is worth comparing with the cost of moving once stamp duty, agents' and legal fees are counted.
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 two-storey rear extension cost in Colwyn Bay?
A two-storey rear extension in Colwyn Bay is priced at £1,670–£2,510 per square metre including VAT as a guide, before kitchen fit-out and fees. Prices in Wales sit below our West Midlands baseline; sloping sites are the main variable.
| Size | Guide price inc VAT |
|---|---|
| 3 m × 5 m footprint, two floors (30 m²) | £50,000–£75,500 |
| 4 m × 6 m footprint, two floors (48 m²) | £80,500–£120,500 |
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 two-storey rear extension in Colwyn Bay?
The planning route for a two-storey rear extension in Colwyn Bay is set by Wales's householder rules and your council.
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. 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?
Colwyn Bay has Victorian terraces near the centre and semis further out. Welsh permitted development allows up to 4 metres at the rear for many houses.
How a two-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.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Approvals
Permitted development check or householder planning application, then Building Regulations drawings to the Welsh Approved Documents and structural calculations, plus party wall notices where they apply.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Two-storey rear extensions near Colwyn Bay
Close by, we work in Llandudno, about 4.8 miles away, and Abergele, about 6.0 miles away.
- Two-storey rear extension in Llandudno
- Two-storey rear extension in Abergele
- Two-storey rear extension in Rhyl
- Two-storey rear extension in Prestatyn
- Two-storey rear extension in Bangor
Other work in Colwyn Bay:
FAQ
Two-storey rear extension questions in Colwyn Bay
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.
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 it be built on a terraced house?
Sometimes, but the upper floor is harder to get through planning on a terrace because of the effect on neighbours. A single-storey extension with a loft conversion is often an easier route.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Is the site visit in Colwyn Bay free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
How much does a two-storey rear extension cost in Colwyn Bay?
As a guide, £1,670–£2,510 per square metre including VAT for a standard specification. For example, 3 m × 5 m footprint, two floors (30 m²): about £50,000–£75,500 at that rate. Your written price follows the survey.