Double-storey extensions in Trowbridge

Covering Trowbridge

Alongside Trowbridge, we also cover Bath, Frome (8 miles to the south-west) and Warminster.

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 do you get with 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.

Measured survey, design and planning drawings
Foundations, steelwork, brick and block walls, roof
Windows, insulation, plastering, electrics and plumbing

What is the guide price for a double-storey extension in Trowbridge?

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

Do you need permission for a double-storey extension in Trowbridge?

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 change the price or programme?

Side extensions close to a boundary are often set back or stepped down so they do not create a terraced effect.
The new roof is tied into the old one, so roof tiles and ridge details need to match.

What happens after I enquire?

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.
We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.

Questions about a double-storey extension in Trowbridge

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 Trowbridge?

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

Also covering

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