Northamptonshire
Side return extensions in Northamptonshire
Infilling the narrow passage beside a Victorian or Edwardian back addition. We design and build rear extensions across Northamptonshire, from Northampton and Corby to Kettering, covering single-storey kitchen extensions, two-storey additions, side returns and wraparounds.

Side return projects in Northampton usually start with a drainage survey of the side passage. Red-brick terraces and semis are typical of Northamptonshire. Coal-mining legacy areas in parts of the East Midlands can need a Coal Authority check before foundations are designed.
How much does a side return extension cost in Northamptonshire?
In Northamptonshire, our guide for a side return extension is £2,230–£3,690 per square metre including VAT for a standard specification. East Midlands prices sit a little below our West Midlands baseline.
| Size | Guide price inc VAT |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £27,000–£44,000 |
| 2.5 m wide × 7 m deep (17.5 m²) | £39,000–£64,500 |
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 Northamptonshire?
Side return infills and the side leg of a wraparound are treated as side extensions in England: single-storey, no more than 4 metres high and no wider than half the original house. They are not permitted development in conservation areas, National Parks or National Landscapes, and a joined wraparound often needs a planning application because the side and rear rules apply together.
The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in Northamptonshire 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 Northamptonshire?
We cover 8 towns and districts in Northamptonshire, including Northampton, Corby and Kettering.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.