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 Keighley?
In Keighley, a side extension typically costs £1,600–£2,450 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £45,000–£68,500. Prices across Yorkshire and the Humber are typically 7% below the UK average for this kind of work, which is reflected in the range for Keighley. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £32,000–£49,000 |
| Typical project (28 m²) | £45,000–£68,500 |
| Larger project (39 m²) | £62,500–£95,500 |
| Rate per m² | £1,600–£2,450 |
What moves the price most:
- Single or two storeys
- Steel work where the side wall is opened
- Roof design and tile matching
- Boundary walls and access for materials
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 extension in Keighley?
Before anything is built in Keighley, we confirm which approvals apply in England. In England a single-storey side extension can be permitted development if it is no more than 4 metres high and no wider than half the width of the original house. Side extensions of more than one storey always need planning permission, as do side extensions in conservation areas, National Parks and National Landscapes.
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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
Handled as part of most side extensions:
- Survey of the boundary, drains and access
- Electrics, heating and plastering
- Planning drawings and application
- Foundations and drainage alterations
- Walls, roof and windows to match the house
- Opening into the existing house
How long does it take?
Expect 10 to 16 weeks on site depending on size and storeys. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in Keighley
In Yorkshire, through-terraces and back-to-backs have particular constraints, while semis and detached houses suit larger extensions.
If your home is in Keighley or close by in Bingley, Shipley and Guiseley, a free home visit is the first step.
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
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about side extensions in Keighley
Will a two-storey side extension look odd?
Not if it is designed well. Setting it back from the front and keeping the roof lower than the main ridge usually gives a natural look and is what most councils ask for.
How much does a side extension cost in Keighley?
In Keighley, a side extension typically costs £1,600–£2,450 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £45,000–£68,500. Your fixed price depends on the survey and drawings.
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.
Do you build side extensions in Keighley?
Yes. We build side extensions across Keighley, including postcodes BD21. Every project starts with a free home visit.
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.