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 Keighley?
In Keighley, 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. Prices across Yorkshire and the Humber are typically 7% below the UK average for this kind of work, which is reflected in the range for Keighley. 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:
- Party wall surveyor fees
- Moving drains and soil stacks
- Steel beams and propping of the back addition
- Glazed roof specification
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 Keighley?
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
From survey to sign-off, the job normally involves:
- Building control sign-off
- Survey of party walls, drains and the existing back addition
- Steel beams to remove the side wall
- Foundations and drainage, including any build-over agreement
- Party wall advice and notices
- Floor levelling, heating and electrics
How long does it take?
Allow 10 to 14 weeks on site. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in Keighley
Yorkshire and the Humber has stone and brick terraces as well as inter-war and newer estates, so materials matching is an early design question.
Projects in Keighley (BD21) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about side return extensions in Keighley
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 Keighley?
In Keighley, 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.
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.
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.
How long does a side return extension take in Keighley?
Typically 10 to 14 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
