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 West Yorkshire?
In West Yorkshire, a side return extension typically costs £2,150–£3,050 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £26,000–£36,500. That range is adjusted for Yorkshire and the Humber, where domestic building work typically costs around 7% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £17,000–£24,500 |
| Typical project (12 m²) | £26,000–£36,500 |
| Larger project (17 m²) | £36,500–£52,000 |
| Rate per m² | £2,150–£3,050 |
What moves the price most:
- Moving drains and soil stacks
- Glazed roof specification
- Access through the house for materials
- 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 West Yorkshire?
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.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
What we take care of:
- Party wall advice and notices
- Survey of party walls, drains and the existing back addition
- Building control sign-off
- Foundations and drainage, including any build-over agreement
- Drawings and planning or permitted development check
- Glazed or solid roof with insulation
How long does it take?
Build time is typically 10 to 14 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in West Yorkshire
In Yorkshire, through-terraces and back-to-backs have particular constraints, while semis and detached houses suit larger extensions.
Towns we cover in West Yorkshire include Leeds, Bradford, Huddersfield, Wakefield, Halifax and Dewsbury.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about side return extensions in West Yorkshire
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.
How do you get materials in?
Mid-terrace houses often have no rear access, so materials come through the house. We protect floors and plan deliveries carefully.
Who approves a side return extension in West Yorkshire?
Planning matters in West Yorkshire go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much space does a side return add?
Typically 1.5 to 2.5 metres of width along the back addition. It often turns a narrow galley kitchen into a family kitchen-diner.
How much does a side return extension cost in West Yorkshire?
In West Yorkshire, a side return extension typically costs £2,150–£3,050 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £26,000–£36,500. Your fixed price depends on the survey and drawings.
