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 Bishop Auckland?
In Bishop Auckland, 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 |
The biggest cost drivers are:
- Roof design and tile matching
- Internal fit-out of the new rooms
- Steel work where the side wall is opened
- Drains, gas meters or soil pipes that need moving
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a side extension in Bishop Auckland?
Here is how the rules work for a side extension 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
On a typical side extension we handle:
- Survey of the boundary, drains and access
- Walls, roof and windows to match the house
- Foundations and drainage alterations
- Building control completion
- Structural calculations
- Planning drawings and application
How long does it take?
The build itself usually takes 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 Bishop Auckland
Across the North East, colliery-era terraces and newer estates sit side by side, so the right project depends on the house type.
Our Bishop Auckland coverage includes postcode districts DL14, and we also work in nearby places such as Newton Aycliffe, Durham and Darlington.
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 pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 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 Bishop Auckland
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.
Do you build side extensions in Bishop Auckland?
Yes. We build side extensions across Bishop Auckland, including postcodes DL14. Every project starts with a free home visit.
How much does a side extension cost in Bishop Auckland?
In Bishop Auckland, 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.
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.