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 Tyne and Wear?
In Tyne and Wear, a side extension typically costs £1,550–£2,400 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £43,500–£67,000. That range is adjusted for the North East, where domestic building work typically costs around 10% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £31,000–£48,000 |
| Typical project (28 m²) | £43,500–£67,000 |
| Larger project (39 m²) | £60,500–£93,500 |
| Rate per m² | £1,550–£2,400 |
What moves the price most:
- Boundary walls and access for materials
- Roof design and tile matching
- Single or two storeys
- Internal fit-out of the new rooms
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 Tyne and Wear?
Before anything is built in Tyne and Wear, we confirm which approvals apply 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
The work we manage on a side extension:
- Planning drawings and application
- Foundations and drainage alterations
- Electrics, heating and plastering
- Opening into the existing house
- Building control completion
- Walls, roof and windows to match the house
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 Tyne and Wear
Across the North East, colliery-era terraces and newer estates sit side by side, so the right project depends on the house type.
Towns we cover in Tyne and Wear include Newcastle upon Tyne, Sunderland, South Shields, Gateshead, Washington and Tynemouth.
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 handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about side extensions in Tyne and Wear
How much does a side extension cost in Tyne and Wear?
In Tyne and Wear, a side extension typically costs £1,550–£2,400 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £43,500–£67,000. Your fixed price depends on the survey and drawings.
Do you build side extensions in Tyne and Wear?
Yes. We build side extensions across Tyne and Wear, including postcodes DH3, DH4, DH5, DH6 and NE1. Every project starts with a free home visit.
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.
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 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.
