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 Stourbridge?
In Stourbridge, 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 Stourbridge 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 |
What moves the price most:
- Single or two storeys
- Drains, gas meters or soil pipes that need moving
- 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 Stourbridge?
Whether you need planning permission depends on your house and its location 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
On a typical side extension we handle:
- Walls, roof and windows to match the house
- Survey of the boundary, drains and access
- Electrics, heating and plastering
- Building control completion
- Foundations and drainage alterations
- Structural calculations
How long does it take?
Expect 10 to 16 weeks on site depending on size and storeys. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Stourbridge
Across the West Midlands, inter-war and post-war semis make up much of the housing, giving good scope for two-storey side extensions and hip-to-gable lofts.
From DY8 outwards, we take on projects throughout Stourbridge and the surrounding parts of the West Midlands.
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 Stourbridge
Who approves a side extension in Stourbridge?
Planning matters in Stourbridge go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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 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.
How much does a side extension cost in Stourbridge?
In Stourbridge, 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.
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.