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 Warwick?
In Warwick, 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 the West Midlands are close to the UK average, so the figures for Warwick 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 |
Your quote will depend mainly on:
- Single or two storeys
- Internal fit-out of the new rooms
- Steel work where the side wall is opened
- Roof design and tile matching
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 Warwick?
The approval route for Warwick is set by planning law 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.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
We check this for your address before design work starts, so there are no surprises later.
What we handle
From survey to sign-off, the job normally involves:
- Foundations and drainage alterations
- Structural calculations
- Survey of the boundary, drains and access
- Planning drawings and application
- Building control completion
- 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 Warwick
The West Midlands has large numbers of 1930s semis and Victorian terraces, which suit rear extensions, side extensions and dormer loft conversions.
We work across Warwick and neighbouring areas such as Leamington Spa, Kenilworth and Stratford-upon-Avon. Postcodes we cover in Warwick include CV34.
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 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 sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about side extensions in Warwick
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 Warwick?
In Warwick, 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.
Who approves a side extension in Warwick?
Planning matters in Warwick go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.
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.