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 Rutland?
In Rutland, 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. The guide for Rutland reflects typical costs in the East Midlands, roughly 5% below the UK-wide figure. 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 |
The biggest cost drivers are:
- Boundary walls and access for materials
- Steel work where the side wall is opened
- Drains, gas meters or soil pipes that need moving
- 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 Rutland?
Approvals for a side extension in Rutland 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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
Handled as part of most side extensions:
- Building control completion
- Walls, roof and windows to match the house
- Foundations and drainage alterations
- Electrics, heating and plastering
- Opening into the existing house
- Survey of the boundary, drains and access
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 Rutland
The East Midlands has a mix of red-brick terraces, inter-war semis and newer estates, so rear extensions and garage conversions are common projects.
Towns we cover in Rutland include Oakham.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 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
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 Rutland
How long does a side extension take in Rutland?
Typically 10 to 16 weeks on site depending on size and storeys. Design and approvals beforehand usually take 3 to 4 months.
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 I build a side extension without planning permission?
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 original house, and the house is not in a conservation area or similar protected land. Two-storey side extensions always need planning permission.
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 Rutland?
In Rutland, 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.
