Swansea Bay
Side return extensions in Swansea Bay
Infilling the narrow passage beside a Victorian or Edwardian back addition. Rear extensions in Swansea Bay: we cover 6 towns including Swansea, Neath and Briton Ferry, with design, approvals and the build under one contract.

Side return projects in Swansea usually start with a drainage survey of the side passage. Swansea 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 much does a side return extension cost in Swansea Bay?
A side return extension in Swansea Bay is priced at £2,140–£3,530 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 |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £25,500–£42,500 |
| 2.5 m wide × 7 m deep (17.5 m²) | £37,500–£62,000 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission in Swansea Bay?
Welsh side-extension rules limit a single-storey side addition to 4 metres high and a 50% increase in the width of the original house, with tighter limits in conservation areas. Wraparounds usually need a planning application.
In Wales, as in England, the Party Wall etc. Act 1996 requires notice to neighbours before work to a shared wall or excavation near their foundations.
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
How much space does a side return add?
Typically 8 to 18 square metres, enough to turn a galley kitchen into a kitchen-diner with an island.
Do I need my neighbour's permission?
Not their permission, but in England and Wales you must serve party wall notices, and a neighbour can consent in writing or ask for a surveyor's award.
Can I combine a side return with a rear extension?
Yes; that is a wraparound extension, and it gives the biggest open-plan room a terrace can have.
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.