Somerset
Rear extensions in Bath
Rear extensions in Bath: single-storey and two-storey extensions, side returns, wraparounds and glass-led designs, planned around stone and rendered houses and the English rules.
Bath is in Somerset, with postcode districts including BA1 and BA2. The nearest places we also cover are Keynsham (6.4 miles) and Neston (7.4 miles).
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
Rear extensions we build in Bath
- Single-storey rear extensions
- Two-storey rear extensions
- Kitchen-diner rear extensions
- Side return extensions
- Wraparound extensions
- Glazed and glass-box rear extensions
- Rear extensions for terraced houses
- Rear extensions for semi-detached houses
- Rear extensions for bungalows
- Rear extension plans and planning applications
Also available across Somerset:
- Rear extensions for detached houses
- Flat-roof rear extensions
- Pitched and lean-to roof rear extensions
- Knocking through to a rear extension
- Roof lanterns and rooflights for rear extensions
- Permitted development rear extensions
- Larger home extension prior approval (England)
- Building Regulations for rear extensions
Rear extension prices in Bath
South West prices run slightly above our West Midlands baseline; natural stone to match the house is the main variable.
| Example | Guide inc VAT |
|---|---|
| Single-storey, 3 m × 4 m (12 m²) | £23,500–£38,500 |
| Single-storey, 4 m × 6 m (24 m²) | £47,500–£77,500 |
| Two-storey, 3 m × 5 m footprint (30 m²) | £56,000–£84,000 |
| Side return, about 14 m² | £33,500–£55,500 |
| Wraparound, about 25 m² | £57,000–£93,500 |
What are homes in Bath like to extend?
Stone-built and rendered houses are common around Bath, so matching the walling is a design decision in its own right: natural stone, reconstituted stone or a render finish across old and new.
Planning rules for Bath
In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.
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.
Planning and Building Regulations are separate in England: even a permitted development extension is inspected for foundations, drainage, structure, insulation, fire safety and ventilation, through the council or a registered building control approver, ending with a completion certificate.
Nearby towns
FAQ
Questions people ask
How much is a rear extension in Bath?
A 3 m × 4 m single-storey rear extension is about £23,500–£38,500 including VAT at our South West England guide rates; the written price follows a survey.
Do I need planning permission in Bath?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Is the site visit in Bath free?
Yes, with no obligation.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.