South Wales Valleys
Side return extensions in the South Wales Valleys
Infilling the narrow passage beside a Victorian or Edwardian back addition. We design and build rear extensions across the South Wales Valleys, from Rhondda and Tonypandy to Bridgend, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.

Side returns suit the Victorian and Edwardian terraces found across parts of the South Wales Valleys, where the kitchen sits in a narrow back addition. Stone terraces along the valley floors and post-war semis higher up are typical of the South Wales Valleys. Sloping sites are common, so floor levels and retaining walls are designed at the start.
How much does a side return extension cost in the South Wales Valleys?
A side return extension in the South Wales Valleys 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 |
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 the South Wales Valleys?
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 the South Wales Valleys 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 the South Wales Valleys?
We cover 27 towns and districts in the South Wales Valleys, including Rhondda, Tonypandy and Bridgend.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.