Double-storey extensions in Corsham

Covering Corsham

Corsham is about 19 miles south-west of Swindon. We also cover Chippenham (3 miles to the north-east), Calne and Trowbridge.

Homes in the South West

The South West mixes stone and render cottages, Victorian terraces in the larger towns and modern estates, and many historic centres are conservation areas where materials and roof shapes are closely controlled.

What goes into a double-storey extension?

Two-storey work has to sit comfortably with the house and the neighbours, so most of the design effort goes into the roofline, window positions and how the new first floor connects to the landing. We handle the planning application, the structural design and the building control process, then build, roof and finish both floors.

Structural engineer’s design and calculations
Windows, insulation, plastering, electrics and plumbing
Joining the new first floor to the existing landing

How much does a double-storey extension cost in Corsham?

What double-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.

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

What approvals does a double-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.

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. Expect around eight weeks for a decision once the application is validated.

What can affect a double-storey extension?

The new roof is tied into the old one, so roof tiles and ridge details need to match.
The first-floor link can mean moving a bathroom or reshaping the landing.

What are the steps?

Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
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

How long does a two-storey extension take?

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

Will we need to move out?

Most people stay. The noisiest stage is when we break through into the existing first floor, which we plan for a short window.

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

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

Other towns nearby

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