What is a side return extension?
A side return extension fills the narrow passage that runs alongside the back addition of many Victorian and Edwardian terraced houses. It widens a galley kitchen into a proper kitchen-diner, usually with a sloping glazed roof to keep the room bright.
How much does a side return extension cost in Bolton?
In Bolton, a side return extension typically costs £2,150–£3,100 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £26,000–£37,000. That range is adjusted for the North West, where domestic building work typically costs around 6% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £17,000–£25,000 |
| Typical project (12 m²) | £26,000–£37,000 |
| Larger project (17 m²) | £36,500–£52,500 |
| Rate per m² | £2,150–£3,100 |
The main things that change the cost:
- Access through the house for materials
- Party wall surveyor fees
- Glazed roof specification
- Length of the side return
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a side return extension in Bolton?
Whether you need planning permission depends on your house and its location in England. In England a side return infill is treated as a side extension. It may be permitted development if it is single-storey, no more than 4 metres high and no wider than half the original house, but not in a conservation area. Because side returns sit on the boundary, party wall notices are almost always needed.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
We check this for your address before design work starts, so there are no surprises later.
What we handle
The work we manage on a side return extension:
- Glazed or solid roof with insulation
- Building control sign-off
- Steel beams to remove the side wall
- Party wall advice and notices
- Floor levelling, heating and electrics
- Drawings and planning or permitted development check
How long does it take?
Allow 10 to 14 weeks on site. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Bolton
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
Projects in Bolton (BL1, BL11 and BL78) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about side return extensions in Bolton
Is a glass roof too hot or cold?
Modern solar-control double or triple glazing reduces glare and heat loss. Building regulations also limit how much glazing you can have unless the design shows it performs well enough.
Will I need a party wall agreement?
Almost certainly in England and Wales, because side returns sit on or near the boundary. Notices must be served before work starts, and a party wall surveyor may be appointed if the neighbour does not consent.
Who approves a side return extension in Bolton?
Planning matters in Bolton go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much does a side return extension cost in Bolton?
In Bolton, a side return extension typically costs £2,150–£3,100 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £26,000–£37,000. Your fixed price depends on the survey and drawings.
Can I stay in the house?
Usually, though the kitchen will be out of action for several weeks. We plan a temporary kitchen area where possible.