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 Ashton-under-Lyne?
In Ashton-under-Lyne, a side extension typically costs £1,600–£2,500 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £45,000–£70,000. Prices across the North West are typically 6% below the UK average for this kind of work, which is reflected in the range for Ashton-under-Lyne. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £32,000–£50,000 |
| Typical project (28 m²) | £45,000–£70,000 |
| Larger project (39 m²) | £62,500–£97,500 |
| Rate per m² | £1,600–£2,500 |
What moves the price most:
- Drains, gas meters or soil pipes that need moving
- Boundary walls and access for materials
- Steel work where the side wall is opened
- Internal fit-out of the new rooms
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 Ashton-under-Lyne?
The approval route for Ashton-under-Lyne 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.
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:
- Opening into the existing house
- Building control completion
- Walls, roof and windows to match the house
- Planning drawings and application
- Survey of the boundary, drains and access
- Foundations and drainage alterations
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 Ashton-under-Lyne
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
Projects in Ashton-under-Lyne (OL7) are surveyed in person before we quote, so the price reflects your actual property.
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 pricing
Design options, then a fixed quote based on the chosen drawings and 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 Ashton-under-Lyne
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 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.
How much does a side extension cost in Ashton-under-Lyne?
In Ashton-under-Lyne, a side extension typically costs £1,600–£2,500 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £45,000–£70,000. Your fixed price depends on the survey and drawings.
Who approves a side extension in Ashton-under-Lyne?
Planning matters in Ashton-under-Lyne 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.