Single-storey extensions in Wiltshire

Covering Wiltshire

We cover Wiltshire, including Swindon, Salisbury, Trowbridge and Chippenham, and the towns around them.

Homes in the South West

In the South West, matching local stone, render or slate is often the main design question, and conservation areas and listed buildings are common in historic towns.

What does a single-storey extension involve?

We design the extension around how you use the house: where the light comes from, how the new room joins the old one, and what happens to the drains and the garden. The structure is built in brick or block to match the house, finished with a flat roof and lantern or a pitched roof, then insulated, plastered and handed back ready to decorate.

Measured survey and design drawings
Foundations, drainage and structural steel
First-fix and second-fix electrics, plastering and making good

How much does a single-storey extension cost in Wiltshire?

Use these ranges to budget for single-storey extensions; the survey turns them into a fixed price for the agreed specification.

Single-storey extensions	Guide price incl. VAT
Standard specification	£2,600 to £3,000 per m²
Good specification	£3,000 to £3,500 per m²
High specification	£3,500 to £4,000 per m²

What approvals does a single-storey extension need in England?

English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.

In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.

What should Wiltshire homeowners check first?

Drains under the footprint may need diverting or a build-over agreement with the water company.
Kitchens and doors have long lead times, so we order them early.

How does the project run?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
Construction and completion. One site lead co-ordinates every trade through to the building control certificate.

Questions about a single-storey extension in Wiltshire

How long does a single-storey extension take to build?

The build itself usually takes 10 to 16 weeks once work starts on site. Design, approvals and ordering usually add 6 to 12 weeks before that.

Do you need to dig up the drains?

Sometimes. If a public sewer runs under the extension, the water company has to agree a build-over or a diversion. We check this at survey stage.

Who deals with the council for a project in Wiltshire?

We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.

Also covering

Learn more about single-storey extensions, or see every project we cover in Wiltshire.