North Wales
Rear extensions for detached houses in North Wales
Wider, deeper rear extensions with room for vaulted roofs and big glazing. We design and build rear extensions across North Wales, from Wrexham and Buckley to Deeside, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.
Older terraces near the centre and post-war semis further out are typical of North Wales. Sloping sites are common in Wales, so floor levels and retaining walls are designed at the start.
How much does a detached house rear extension cost in North Wales?
A detached house rear extension in North Wales is priced at £1,810–£2,980 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 |
|---|---|
| 4 m wide × 6 m deep (24 m²) | £43,500–£71,500 |
| 5 m wide × 8 m deep (40 m²) | £72,500–£119,000 |
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 in North Wales?
In Wales a single-storey rear extension can often be permitted development if it projects no more than 4 metres beyond the rear wall and is no more than 4 metres high. Wales has no prior approval route for deeper extensions, so anything bigger needs a householder planning application.
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.
Where in North Wales do we work?
FAQ
Questions people ask
Can I have a vaulted ceiling?
Yes, with a pitched roof and exposed or boxed rafters, subject to the height limits.
Is an oak frame worth it?
It is a premium finish with a long life; it costs more than blockwork with a plain roof.
Do I need party wall notices?
Only if the extension is close enough to a neighbour's building for the excavation rules to apply.
Do you cover all of North Wales?
We cover 14 towns and districts in North Wales, including Wrexham, Buckley and Deeside.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.