What is a side extension?

A side extension builds into the space beside a semi-detached or detached house, often over a driveway or side passage. It can be single-storey, for a utility room, downstairs toilet or study, or two-storey to add a bedroom above.
How much does a side extension cost in East Kilbride?
In East Kilbride, a side extension typically costs £1,650–£2,550 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £46,000–£71,500. Building costs in Scotland are close to the UK average, so the figures for East Kilbride are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £33,000–£51,000 |
| Typical project (28 m²) | £46,000–£71,500 |
| Larger project (39 m²) | £64,500–£99,500 |
| Rate per m² | £1,650–£2,550 |
The biggest cost drivers are:
- Internal fit-out of the new rooms
- Single or two storeys
- Drains, gas meters or soil pipes that need moving
- Boundary walls and access 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 extension in East Kilbride?
Approvals for a side extension in East Kilbride follow the rules for Scotland. In Scotland single-storey side extensions can be permitted development if they do not come forward of a side wall facing a road and stay within the height and boundary limits. Two-storey side extensions usually need planning permission, and 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
From survey to sign-off, the job normally involves:
- Walls, roof and windows to match the house
- Opening into the existing house
- Survey of the boundary, drains and access
- Structural calculations
- Foundations and drainage alterations
- Building control completion
How long does it take?
Allow 10 to 16 weeks on site depending on size and storeys. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in East Kilbride
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.
East Kilbride sits in Lanarkshire, about 6 miles west of Hamilton. We cover the whole of East Kilbride, including postcodes G74.
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
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed 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 extensions in East Kilbride
Who approves a side extension in East Kilbride?
Planning matters in East Kilbride go to the council covering your address, and the work needs a building warrant. We prepare and submit the applications for you.
How long does it take?
Roughly 10 to 16 weeks on site once approvals are in place, depending on whether it is one or two storeys.
Do I need planning permission for a side extension in East Kilbride?
In Scotland single-storey side extensions can be permitted development if they do not come forward of a side wall facing a road and stay within the height and boundary limits. Two-storey side extensions usually need planning permission, and a building warrant is needed before work starts.
Can a side extension go over a drain?
Often yes, with a build-over agreement from the water company or by rerouting the drain. We check this during the survey.
Will I lose my driveway?
A side extension often takes the side drive. We look at whether parking can be kept at the front and whether a dropped kerb is needed.
How much does a side extension cost in East Kilbride?
In East Kilbride, a side extension typically costs £1,650–£2,550 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £46,000–£71,500. Your fixed price depends on the survey and drawings.
