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 St Andrews?
In St Andrews, a side return extension typically costs £2,250–£3,200 per m² of floor area, including VAT at 20% (standard rate). For a typical 12 m² project that is roughly £27,000–£38,500. Building costs in Scotland are close to the UK average, so the figures for St Andrews are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (8 m²) | £18,000–£25,500 |
| Typical project (12 m²) | £27,000–£38,500 |
| Larger project (17 m²) | £38,000–£54,500 |
| Rate per m² | £2,250–£3,200 |
The biggest cost drivers are:
- Steel beams and propping of the back addition
- Access through the house for materials
- Agreements with neighbours on shared walls
- Moving drains and soil stacks
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 St Andrews?
Here is how the rules work for a side return extension in Scotland. In Scotland a single-storey infill beside a back addition can be permitted development within the height and boundary limits, but not in a conservation area. A building warrant is needed before work starts.
In Scotland a building warrant is needed before work starts on most extensions, loft conversions and conversions. It is issued by the council’s building standards service. When the work is finished, a completion certificate is submitted and accepted by the council after inspection.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
The work we manage on a side return extension:
- Written agreement with neighbours on shared walls
- Building control sign-off
- Floor levelling, heating and electrics
- Written agreement with neighbours on shared walls
- Glazed or solid roof with insulation
- Foundations and drainage, including any build-over agreement
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 St Andrews
Scotland’s housing ranges from sandstone tenements and villas to post-war and modern estates, and the building warrant system shapes how projects are planned.
If your home is in St Andrews or close by in Cupar, Dundee and Leven, a free home visit is the first step.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 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 sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about side return extensions in St Andrews
Do I need planning permission for a side return extension in St Andrews?
In Scotland a single-storey infill beside a back addition can be permitted development within the height and boundary limits, but not in a conservation area. A building warrant is needed before work starts.
How much does a side return extension cost in St Andrews?
In St Andrews, a side return extension typically costs £2,250–£3,200 per m² of floor area, including VAT at 20% (standard rate). A typical 12 m² project comes to roughly £27,000–£38,500. Your fixed price depends on the survey and drawings.
How long does a side return extension take in St Andrews?
Typically 10 to 14 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
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.
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.
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.
