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 Stockton-on-Tees?
In Stockton-on-Tees, a side return extension typically costs £2,050–£2,950 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £24,500–£35,500. The guide for Stockton-on-Tees reflects typical costs in the North East, roughly 10% below the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £16,500–£23,500 |
| Typical project (12 m²) | £24,500–£35,500 |
| Larger project (17 m²) | £35,000–£50,000 |
| Rate per m² | £2,050–£2,950 |
What moves the price most:
- Moving drains and soil stacks
- Party wall surveyor fees
- Steel beams and propping of the back addition
- Length of the side return
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 Stockton-on-Tees?
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.
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
Handled as part of most side return extensions:
- Steel beams to remove the side wall
- Building control sign-off
- Foundations and drainage, including any build-over agreement
- Party wall advice and notices
- Floor levelling, heating and electrics
- Drawings and planning or permitted development check
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 Stockton-on-Tees
The North East has many terraced streets and post-war semis, where rear extensions and loft conversions are popular ways to gain space.
From TS19 outwards, we take on projects throughout Stockton-on-Tees and the surrounding parts of County Durham.
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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 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 Stockton-on-Tees
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 do you get materials in?
Mid-terrace houses often have no rear access, so materials come through the house. We protect floors and plan deliveries carefully.
How much does a side return extension cost in Stockton-on-Tees?
In Stockton-on-Tees, a side return extension typically costs £2,050–£2,950 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £24,500–£35,500. Your fixed price depends on the survey and drawings.
Who approves a side return extension in Stockton-on-Tees?
Planning matters in Stockton-on-Tees go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.