West Wales
Permitted development rear extensions in West Wales
Designing to the no-application limits, with a lawful development certificate as proof. Rear extensions in West Wales: we cover 6 towns including Llanelli, Aberystwyth and Carmarthen, with design, approvals and the build under one contract.

West Wales 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 much does a permitted development rear extension cost in West Wales?
A permitted development rear extension in West Wales is priced at £1,770–£2,880 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 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 in West Wales?
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.
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 West Wales do we work?
FAQ
Questions people ask
Is permitted development the same as planning permission?
No; it is a national grant of permission for work within set limits, so no application is needed.
Do I still need Building Regulations?
Yes, always.
Can my neighbours object?
Not to permitted development itself, though they can ask the council to check it complies. Prior approval does involve neighbour consultation.
Do you cover all of West Wales?
We cover 6 towns and districts in West Wales, including Llanelli, Aberystwyth and Carmarthen.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.