Single-storey extensions in Dorchester

Covering Dorchester

Alongside Dorchester, we also cover Weymouth (7 miles to the south), Bridport and Yeovil.

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 do you get with a single-storey extension?

A single-storey extension adds one level of new floor space to the back or side of a house, usually to open up a kitchen, dining or family room. It is the most common way to gain space without moving, and many can be built without a planning application.

Measured survey and design drawings
Building control application and inspections
First-fix and second-fix electrics, plastering and making good

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

Guide prices for single-storey extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.

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?

In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.

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.

What should I think about before starting?

Building on or near a shared boundary usually means serving a party wall notice in England and Wales.
Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.

From first call to completion

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Your questions answered

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.

Do you work in Dorchester?

Yes. Dorchester is within our coverage for single-storey extensions, along with nearby Weymouth and Bridport.

Also covering

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