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 Weston-super-Mare?
In Weston-super-Mare, a side return extension typically costs £2,350–£3,350 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £28,000–£40,000. Prices in the South West sit near the national average for this kind of work, and the range for Weston-super-Mare reflects that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £19,000–£27,000 |
| Typical project (12 m²) | £28,000–£40,000 |
| Larger project (17 m²) | £40,000–£57,000 |
| Rate per m² | £2,350–£3,350 |
Your quote will depend mainly on:
- Length of the side return
- 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 Weston-super-Mare?
The approval route for Weston-super-Mare is set by planning law 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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
On a typical side return extension we handle:
- Floor levelling, heating and electrics
- Glazed or solid roof with insulation
- Building control sign-off
- Foundations and drainage, including any build-over agreement
- Survey of party walls, drains and the existing back addition
- Drawings and planning or permitted development check
How long does it take?
The build itself usually takes 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 Weston-super-Mare
In parts of the South West, protected landscapes and conservation areas shape what can be built, so materials and roof forms are chosen carefully.
Projects in Weston-super-Mare (BS23) are surveyed in person before we quote, so the price reflects your actual property.
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 pricing
Design options, then a fixed quote based on the chosen drawings and 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 Weston-super-Mare
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.
How long does a side return extension take in Weston-super-Mare?
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 Weston-super-Mare?
In Weston-super-Mare, a side return extension typically costs £2,350–£3,350 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £28,000–£40,000. 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.
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.
