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 Taunton?
In Taunton, a side extension typically costs £1,750–£2,700 per m² of floor area, including VAT at 20% (standard rate). For a typical 28 m² project that is roughly £49,000–£75,500. Building costs in the South West are close to the UK average, so the figures for Taunton are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (20 m²) | £35,000–£54,000 |
| Typical project (28 m²) | £49,000–£75,500 |
| Larger project (39 m²) | £68,000–£105,500 |
| Rate per m² | £1,750–£2,700 |
The biggest cost drivers are:
- Steel work where the side wall is opened
- Single or two storeys
- Roof design and tile matching
- 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 Taunton?
Before anything is built in Taunton, 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most side extensions:
- Electrics, heating and plastering
- Survey of the boundary, drains and access
- Planning drawings and application
- Foundations and drainage alterations
- Structural calculations
- Building control completion
How long does it take?
Allow 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 Taunton
The South West mixes stone and render cottages with post-war and newer estates, and local materials matter more here when matching an extension.
Taunton sits in Somerset. We cover the whole of Taunton, including postcodes TA1.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 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 Taunton
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 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 Taunton?
In Taunton, a side extension typically costs £1,750–£2,700 per m² of floor area, including VAT at 20% (standard rate). A typical 28 m² project comes to roughly £49,000–£75,500. Your fixed price depends on the survey and drawings.
Who approves a side extension in Taunton?
Planning matters in Taunton go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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.