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 Harwich?
In Harwich, 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. Building costs in the East of England run about 6% above the UK average, and the figures for Harwich are adjusted to reflect that. 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 main things that change the cost:
- Party wall surveyor fees
- Access through the house for materials
- 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 Harwich?
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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
The work we manage on a side return extension:
- Glazed or solid roof with insulation
- Party wall advice and notices
- Survey of party walls, drains and the existing back addition
- Drawings and planning or permitted development check
- Building control sign-off
- Floor levelling, heating and electrics
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 Harwich
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
Harwich sits in Essex, about 38 miles north-east of Chelmsford. We cover the whole of Harwich, including postcodes CO12.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about side return extensions in Harwich
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.
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.
How long does a side return extension take in Harwich?
Typically 10 to 14 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
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 much does a side return extension cost in Harwich?
In Harwich, 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.