Bristol and South Gloucestershire
Rear extensions for semi-detached houses in Bristol and South Gloucestershire
Single or two-storey extensions for semi-detached houses, with side access and one party wall. Rear extensions in Bristol and South Gloucestershire: we cover 6 towns including Bristol, Kingswood and Mangotsfield, with design, approvals and the build under one contract.
In Bristol we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours. Stone-built and rendered houses are common around Bristol and South Gloucestershire, 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 semi-detached rear extension cost in Bristol and South Gloucestershire?
Guide prices for a semi-detached rear extension in Bristol and South Gloucestershire start from our South West England rate of £1,980–£3,220 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 |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £23,500–£38,500 |
| 4 m wide × 5 m deep (20 m²) | £39,500–£64,500 |
| 4 m wide × 6 m deep (24 m²) | £47,500–£77,500 |
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 Bristol and South Gloucestershire?
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent.
Where in Bristol and South Gloucestershire do we work?
FAQ
Questions people ask
How far can I extend a semi without planning?
3 metres under permitted development in England, or up to 6 metres with prior approval, outside designated land.
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
Single or two-storey on a semi?
Two-storey if you need bedrooms, single-storey if you need a bigger kitchen. Planning risk is lower for single-storey.
Do you cover all of Bristol and South Gloucestershire?
We cover 6 towns and districts in Bristol and South Gloucestershire, including Bristol, Kingswood and Mangotsfield.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.