Swansea Bay
Rear extensions for detached houses in Swansea Bay
Wider, deeper rear extensions with room for vaulted roofs and big glazing. Rear extensions in Swansea Bay: we cover 6 towns including Swansea, Neath and Briton Ferry, with design, approvals and the build under one contract.
Older terraces near the centre and post-war semis further out are typical of Swansea Bay. 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 Swansea Bay?
A detached house rear extension in Swansea Bay 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 |
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 Swansea Bay?
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 Swansea Bay 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 Swansea Bay?
We cover 6 towns and districts in Swansea Bay, including Swansea, Neath and Briton Ferry.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.