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 Runcorn?
In Runcorn, 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. The guide for Runcorn reflects typical costs in the North West, roughly 6% below the UK-wide figure. 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 |
What moves the price most:
- Steel beams and propping of the back addition
- Moving drains and soil stacks
- Length of the side return
- Glazed roof specification
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a side return extension in Runcorn?
Approvals for a side return extension in Runcorn 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
On a typical side return extension we handle:
- Party wall advice and notices
- Glazed or solid roof with insulation
- Foundations and drainage, including any build-over agreement
- Steel beams to remove the side wall
- Floor levelling, heating and electrics
- Building control sign-off
How long does it take?
Build time is typically 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 Runcorn
Terraced streets across the North West often suit rear dormers and single-storey kitchen extensions.
Runcorn sits in Cheshire, about 12 miles north-east of Chester. We cover the whole of Runcorn, including postcodes WA7.
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
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 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 Runcorn
How much does a side return extension cost in Runcorn?
In Runcorn, 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.
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 long does a side return extension take in Runcorn?
Typically 10 to 14 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
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.
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.