Double-storey extensions in Weymouth

Covering Weymouth

Weymouth sits 7 miles south of Dorchester, with Dorchester 7 miles to the north and Bridport 15 miles to the north-west.

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 goes into a double-storey extension?

A double-storey extension adds new rooms on both the ground and first floor in one build, typically a larger kitchen or living space downstairs and an extra bedroom or bathroom above. Because the roof and foundations are shared, the cost per square metre is usually lower than a single-storey extension.

Measured survey, design and planning drawings
Structural engineer’s design and calculations
Joining the new first floor to the existing landing

What will a double-storey extension cost?

Typical ranges for double-storey extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.

Double-storey extensions	Guide price incl. VAT
Standard specification	£2,400 to £2,900 per m²
Good specification	£2,900 to £3,400 per m²
High specification	£3,400 to £3,850 per m²

Planning and building rules in Weymouth

Projects in England go through two separate checks. Planning (or confirmation that the work is permitted development) comes from the district, borough or unitary council, and building regulations approval comes from the council’s building control team or a registered building control approver. Where work touches a shared wall or digs near a neighbour’s foundations, the Party Wall etc. Act 1996 applies.

Two-storey rear extensions can sometimes be permitted development in England (no more than 3 m deep, at least 7 m from the rear boundary, roof pitch to match), but most two-storey and all two-storey side extensions need householder planning permission.

What can affect a double-storey extension?

Neighbours’ light is assessed using the 45-degree guide many councils use.
The first-floor link can mean moving a bathroom or reshaping the landing.

What happens after I enquire?

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Double-storey extensions: common questions

Does a two-storey extension need planning permission?

Usually yes. In England some two-storey rear extensions are permitted development, but side extensions over one storey always need planning permission.

How long does a two-storey extension take?

Around 14 to 24 weeks on site, plus the planning period before that.

How do I get a price for double-storey extensions in Weymouth?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Double-storey extensions near Weymouth

Learn more about double-storey extensions, or see every project we cover in Weymouth.