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 Castleford?
In Castleford, 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. The guide for Castleford reflects typical costs in Yorkshire and the Humber, roughly 7% below the UK-wide figure. 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:
- Moving drains and soil stacks
- Party wall surveyor fees
- Access through the house for materials
- 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 Castleford?
Here is how the rules work for a side return extension 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:
- Floor levelling, heating and electrics
- Foundations and drainage, including any build-over agreement
- Steel beams to remove the side wall
- Survey of party walls, drains and the existing back addition
- Glazed or solid roof with insulation
- Building control sign-off
How long does it take?
The build itself usually takes 10 to 14 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Castleford
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.
From WF10 outwards, we take on projects throughout Castleford and the surrounding parts of West Yorkshire.
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 sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about side return extensions in Castleford
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.
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.
How long does a side return extension take in Castleford?
Typically 10 to 14 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
How much does a side return extension cost in Castleford?
In Castleford, 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.