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 Ashington?
In Ashington, a side return extension typically costs £2,050–£2,950 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £24,500–£35,500. We start from a UK-wide guide and adjust it for the North East, where labour and materials are typically about 10% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £16,500–£23,500 |
| Typical project (12 m²) | £24,500–£35,500 |
| Larger project (17 m²) | £35,000–£50,000 |
| Rate per m² | £2,050–£2,950 |
The biggest cost drivers are:
- Moving drains and soil stacks
- Length of the side return
- Party wall surveyor fees
- Access through the house for materials
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 Ashington?
The approval route for Ashington 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
On a typical side return extension we handle:
- Survey of party walls, drains and the existing back addition
- Building control sign-off
- Glazed or solid roof with insulation
- Party wall advice and notices
- Floor levelling, heating and electrics
- Steel beams to remove the side wall
How long does it take?
Build time is typically 10 to 14 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Ashington
The North East has many terraced streets and post-war semis, where rear extensions and loft conversions are popular ways to gain space.
We work across Ashington and neighbouring areas such as Bedlington, Blyth and Cramlington. Postcodes we cover in Ashington include NE63.
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
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 handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about side return extensions in Ashington
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 does a side return extension cost in Ashington?
In Ashington, a side return extension typically costs £2,050–£2,950 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £24,500–£35,500. Your fixed price depends on the survey and drawings.
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.
Who approves a side return extension in Ashington?
Planning matters in Ashington go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.
