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 Eastbourne?
In Eastbourne, a side return extension typically costs £2,600–£3,700 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £31,000–£44,500. Prices across the South East are typically 12% above the UK average for this kind of work, which is reflected in the range for Eastbourne. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £21,000–£29,500 |
| Typical project (12 m²) | £31,000–£44,500 |
| Larger project (17 m²) | £44,000–£63,000 |
| Rate per m² | £2,600–£3,700 |
The biggest cost drivers are:
- Length of the side return
- Moving drains and soil stacks
- Glazed roof specification
- Party wall surveyor fees
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 Eastbourne?
Approvals for a side return extension in Eastbourne 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.
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.
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:
- Building control sign-off
- Steel beams to remove the side wall
- Foundations and drainage, including any build-over agreement
- Floor levelling, heating and electrics
- Drawings and planning or permitted development check
- Glazed or solid roof with insulation
How long does it take?
Expect 10 to 14 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Eastbourne
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
We work across Eastbourne and neighbouring areas such as Hailsham, Seaford and Bexhill-on-Sea. Postcodes we cover in Eastbourne include BN21.
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
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about side return extensions in Eastbourne
How much does a side return extension cost in Eastbourne?
In Eastbourne, a side return extension typically costs £2,600–£3,700 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £31,000–£44,500. Your fixed price depends on the survey and drawings.
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 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.
Who approves a side return extension in Eastbourne?
Planning matters in Eastbourne 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.