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 Irlam?
In Irlam, 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. Building costs in the North West run about 6% below the UK average, and the figures for Irlam are adjusted to reflect that. 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:
- Glazed roof specification
- Party wall surveyor fees
- Steel beams and propping of the back addition
- Moving drains and soil stacks
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a side return extension in Irlam?
Approvals for a side return extension in Irlam follow the rules for 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
The work we manage on a side return extension:
- Foundations and drainage, including any build-over agreement
- Party wall advice and notices
- Glazed or solid roof with insulation
- Building control sign-off
- Survey of party walls, drains and the existing back addition
- Drawings and planning or permitted development check
How long does it take?
Allow 10 to 14 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Irlam
Terraced streets across the North West often suit rear dormers and single-storey kitchen extensions.
Our Irlam coverage includes postcode districts M44, and we also work in nearby places such as Urmston, Sale and Stretford.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 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 Irlam
How long does a side return extension take in Irlam?
Typically 10 to 14 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
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 much does a side return extension cost in Irlam?
In Irlam, 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.
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.
Does a side return extension need planning permission?
It depends on the design and where you live. In England a side return can sometimes be permitted development, but side extensions in conservation areas and on many terraced streets need an application. We check your house’s rights before designing.
