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 Lanarkshire?
In Lanarkshire, 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 Lanarkshire 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 |
Your quote will depend mainly on:
- Glazed roof specification
- Steel beams and propping of the back addition
- Access through the house for materials
- Moving drains and soil stacks
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a side return extension in Lanarkshire?
Before anything is built in Lanarkshire, we confirm which approvals apply 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.
Scotland has no Party Wall Act. Work on shared walls is governed by your title deeds, the Tenements (Scotland) Act 2004 for flats, and common law, so we agree arrangements with neighbours in writing 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
Handled as part of most side return extensions:
- Foundations and drainage, including any build-over agreement
- Written agreement with neighbours on shared walls
- Drawings and planning or permitted development check
- Building control sign-off
- Glazed or solid roof with insulation
- Steel beams to remove the side wall
How long does it take?
Expect 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 Lanarkshire
In Scotland, bungalows and one-and-a-half-storey homes are common, so dormer conversions are a popular way to add bedrooms.
Towns we cover in Lanarkshire include East Kilbride, Hamilton, Cumbernauld, Coatbridge, Airdrie and Motherwell.
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 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
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about side return extensions in Lanarkshire
Do I need planning permission for a side return extension in Lanarkshire?
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.
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 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.
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 Lanarkshire?
In Lanarkshire, 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.
Who approves a side return extension in Lanarkshire?
Planning matters in Lanarkshire go to the council covering your address, and the work needs a building warrant. We prepare and submit the applications for you.
