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 Camden?
In Camden, a side return extension typically costs £3,000–£4,300 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £36,000–£51,500. Building costs in London run about 30% above the UK average, and the figures for Camden are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £24,000–£34,500 |
| Typical project (12 m²) | £36,000–£51,500 |
| Larger project (17 m²) | £51,000–£73,000 |
| Rate per m² | £3,000–£4,300 |
What moves the price most:
- Moving drains and soil stacks
- Length of the side return
- Steel beams and propping of the back addition
- Party wall surveyor fees
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 Camden?
Whether you need planning permission depends on your house and its location 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
From survey to sign-off, the job normally involves:
- Building control sign-off
- Floor levelling, heating and electrics
- Glazed or solid roof with insulation
- Survey of party walls, drains and the existing back addition
- Foundations and drainage, including any build-over agreement
- Party wall advice and notices
How long does it take?
Allow 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 Camden
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
We work across Camden and neighbouring areas such as Islington, Highgate and Hampstead. Postcodes we cover in Camden include N1C, NW1W, NW3 and NW26.
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 Camden
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.
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 Camden?
Typically 10 to 14 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
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.
How much does a side return extension cost in Camden?
In Camden, a side return extension typically costs £3,000–£4,300 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £36,000–£51,500. Your fixed price depends on the survey and drawings.