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 Brighouse?
In Brighouse, 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. We start from a UK-wide guide and adjust it for Yorkshire and the Humber, where labour and materials are typically about 7% below average. 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 |
Your quote will depend mainly on:
- Boundary walls and access for materials
- Steel work where the side wall is opened
- Internal fit-out of the new rooms
- Single or two storeys
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a side extension in Brighouse?
Approvals for a side extension in Brighouse follow the rules for 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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
What we take care of:
- Survey of the boundary, drains and access
- Opening into the existing house
- Foundations and drainage alterations
- Walls, roof and windows to match the house
- Building control completion
- Structural calculations
How long does it take?
Expect 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 Brighouse
Yorkshire and the Humber has stone and brick terraces as well as inter-war and newer estates, so materials matching is an early design question.
We work across Brighouse and neighbouring areas such as Halifax, Cleckheaton and Liversedge. Postcodes we cover in Brighouse include HD6.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 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 Brighouse
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.
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.
How much does a side extension cost in Brighouse?
In Brighouse, 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.
How close to the boundary can I build?
You can build up to the boundary, but the eaves height near it is limited under permitted development, and planning officers often want a gap at first floor. If you build on or near a shared boundary, party wall rules may apply.
Who approves a side extension in Brighouse?
Planning matters in Brighouse go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.