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 Horsforth?
In Horsforth, 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. Building costs in Yorkshire and the Humber run about 7% below the UK average, and the figures for Horsforth are adjusted to reflect that. 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 |
Your quote will depend mainly on:
- Party wall surveyor fees
- Access through the house for materials
- Length of the side return
- Glazed roof specification
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a side return extension in Horsforth?
Approvals for a side return extension in Horsforth 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.
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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
On a typical side return extension we handle:
- Survey of party walls, drains and the existing back addition
- Building control sign-off
- Drawings and planning or permitted development check
- Glazed or solid roof with insulation
- Foundations and drainage, including any build-over agreement
- 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 Horsforth
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.
Horsforth sits in West Yorkshire, about 5 miles north-west of Leeds. We cover the whole of Horsforth, including postcodes LS18.
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
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 Horsforth
How much does a side return extension cost in Horsforth?
In Horsforth, 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.
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.
Do you build side return extensions in Horsforth?
Yes. We build side return extensions across Horsforth, including postcodes LS18. Every project starts with a free home visit.
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.
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.