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 Stanford-le-Hope?
In Stanford-le-Hope, a side return extension typically costs £2,450–£3,500 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £29,500–£42,000. That range is adjusted for the East of England, where domestic building work typically costs around 6% above the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £19,500–£28,000 |
| Typical project (12 m²) | £29,500–£42,000 |
| Larger project (17 m²) | £41,500–£59,500 |
| Rate per m² | £2,450–£3,500 |
The biggest cost drivers are:
- Access through the house for materials
- Steel beams and propping of the back addition
- Party wall surveyor fees
- 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 Stanford-le-Hope?
Before anything is built in Stanford-le-Hope, we confirm which approvals apply 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
What we take care of:
- Drawings and planning or permitted development check
- Party wall advice and notices
- Foundations and drainage, including any build-over agreement
- Survey of party walls, drains and the existing back addition
- Steel beams to remove the side wall
- Building control sign-off
How long does it take?
Expect 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 Stanford-le-Hope
Many towns in the East of England have estates built since the 1970s, where garage conversions and rear extensions are popular.
Stanford-le-Hope sits in Essex, about 12 miles west of Southend-on-Sea. We cover the whole of Stanford-le-Hope, including postcodes SS17.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 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 Stanford-le-Hope
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 Stanford-le-Hope?
Yes. We build side return extensions across Stanford-le-Hope, including postcodes SS17. Every project starts with a free home visit.
How much does a side return extension cost in Stanford-le-Hope?
In Stanford-le-Hope, a side return extension typically costs £2,450–£3,500 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £29,500–£42,000. 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.
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.
