Two-storey wraparound extensions in Trowbridge
Adding a two-storey wraparound extension in Trowbridge gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in England.
What we'd confirm first for a project in Trowbridge.
- Postcode districts
- BA14 and BA15
- County / area
- Wiltshire, England
- Price region
- South West England
- Guide price
- £124,000–£170,000 (£2,210–£3,040 per m²)
- Approval route
- Planning permission is needed: the side part takes it outside permitted development in England.
- Nearest towns
- Westbury (4.2 miles), Melksham (4.8 miles), Neston (Wiltshire) (6.5 miles)
- Distance to Swindon
- about 24.7 miles
- First visit
- Free, no obligation
About a two-storey wraparound extension
A two-storey wraparound extension suits a house with space both beside it and behind it, where you want to transform the layout rather than add a single room. You get one design for the whole L-shape, the planning application, structural design for the corner and the openings into the house, building regulations approval and the build, managed by us and carried out by vetted teams working under S&K.
Around Trowbridge we also work in Westbury, Melksham and Neston (Wiltshire), and across the rest of Wiltshire. Postcode districts in and near Trowbridge: BA14 and BA15.
What it costs in Trowbridge
Our guide for South West England is £2,210–£3,040 per m² including VAT. On a project with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space), that puts a two-storey wraparound extension in Trowbridge at roughly £124,000–£170,000. These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.
| Spec | Per m² | An L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space) |
|---|---|---|
| Essential | £2,040–£2,800 per m² | £114,000–£156,500 |
| Standard | £2,210–£3,040 per m² | £124,000–£170,000 |
| Premium | £2,660–£3,650 per m² | £149,000–£204,000 |
Planning and building regulations in Trowbridge
In England, a two-storey wraparound extension needs householder planning permission, because any extension beyond a side wall must be single storey to be permitted development. The application costs £548 (or £575 for applications made from 8 December 2026). Councils weigh the side part against the street scene and the rear part against neighbours' light and outlook, and should decide within 8 weeks of validation.
Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.
Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.
Design points for Trowbridge homes
Daylight to the middle
A deep L-shaped plan can leave the middle of the ground floor dark, because the old rear rooms are now enclosed. We use wide rear openings, a well-placed stair and, where part of the extension is single storey, roof lights, while keeping total glazing within the Part L allowance.
Two roofs that meet
A wraparound needs the side roof and rear roof to join cleanly, often with a valley or hip where they meet. Getting pitches and ridge heights right keeps rainwater moving and avoids a bulky mass at the back corner, which neighbours and planners notice.
How we'd run your project
Measure and listen
A visit to Trowbridge to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Questions about two-storey wraparound extensions in Trowbridge
Do I need planning permission for a two-storey wraparound extension in Trowbridge?
Trowbridge is in England, so England planning rules apply. Planning permission is needed: the side part takes it outside permitted development in England. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.
Who handles building regulations for a project in Trowbridge?
We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
How much does a two-storey wraparound extension cost in Trowbridge?
Our guide for South West England, which covers Trowbridge, is £2,210–£3,040 per m² including VAT. A typical project with an L-shaped footprint of about 28 m² wrapping the side and rear, on two floors (56 m² of new floor space) comes to about £124,000–£170,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Is a wraparound extension better than separate side and rear extensions?
Building both at once usually costs less than two separate projects, because you pay for one set-up, one scaffold, one roof junction and one set of approvals. It also lets the layout be designed as a whole. The trade-off is a larger single outlay and a longer build, often 16 to 24 weeks at this size.
Can a wraparound extension be part single, part two-storey?
Yes. Many wraparounds keep the rear part single storey with roof lights over the kitchen and put the two-storey part to the side. This can reduce the effect on neighbours and the cost. We set out both options at the design stage, so you can compare floor space against price before choosing.
Nearby
Close to Trowbridge? We work across the area, including:
Other extensions in Trowbridge
- Rear
- Side
- Part two-storey
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Trowbridge · Two-storey wraparound extensions across Wiltshire
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Trowbridge.