Cornwall
Side return extensions in Cornwall
Infilling the narrow passage beside a Victorian or Edwardian back addition. Across Cornwall we handle the whole rear extension: survey, drawings, the planning route, building control and the build. Towns we cover here include Redruth, Falmouth and St Austell.

In Redruth we check the boundary line and the neighbour's gutter before drawing a side return, because a few centimetres decide whether the wall goes on or beside the boundary. Stone-built and rendered houses are common around Cornwall, so matching the walling is a design decision in its own right: natural stone, reconstituted stone or a render finish across old and new.
How much does a side return extension cost in Cornwall?
Guide prices for a side return extension in Cornwall start from our South West England rate of £2,390–£3,950 per square metre, including VAT. South West prices run slightly above our West Midlands baseline; natural stone to match the house is the main variable.
| Size | Guide price inc VAT |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £28,500–£47,500 |
| 2.5 m wide × 7 m deep (17.5 m²) | £42,000–£69,000 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission in Cornwall?
In England the side part of a side return or wraparound must meet the side-extension rules (one storey, under 4 metres high, no more than half the width of the original house), and those rights do not apply on designated land. Because a wraparound combines a side and a rear extension, many need householder planning permission.
Because rear extensions often sit on or near the boundary, the Party Wall etc. Act 1996 usually applies in England. Notices go out one or two months before work depending on the type of work, and a surveyor's award is only needed if a neighbour does not consent.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in Cornwall 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 Cornwall?
We cover 10 towns and districts in Cornwall, including Redruth, Falmouth and St Austell.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.