First-floor extensions in Neston (Wiltshire)

The basics for Neston (Wiltshire) at a glance.

Postcode districts: SN13
County / area: Wiltshire, England
Price region: South West England
Guide price: £26,000–£37,500 (£1,850–£2,680 per m²)
Approval route: It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
Nearest towns: Corsham (1.7 miles), Melksham (3.8 miles), Chippenham (4.6 miles)
Distance to Swindon: about 20.7 miles
First visit: Free, no obligation

About a first-floor extension

A first-floor extension suits you if your house already has a single-storey extension and you need more space upstairs. You get a structural check of the existing walls and foundations, a design that ties the new floor into the house, the approvals your nation needs, building regulations approval and the build, managed by us and carried out by vetted teams working under S&K.

Around Neston (Wiltshire) we also work in Corsham, Melksham and Chippenham, and across the rest of Wiltshire. Postcode district in and near Neston (Wiltshire): SN13.

What it costs in Neston (Wiltshire)

Expect a first-floor extension in Neston (Wiltshire) to land somewhere around £26,000–£37,500 for 4 m × 3.5 m of new first-floor space (14 m²). Our South West England guide rate is £1,850–£2,680 per m², including VAT. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	4 m × 3.5 m of new first-floor space (14 m²)
Essential	£1,710–£2,460 per m²	£24,000–£34,500
Standard	£1,850–£2,680 per m²	£26,000–£37,500
Premium	£2,220–£3,210 per m²	£31,000–£45,000

Planning and building regulations in Neston (Wiltshire)

In England, adding a first floor turns a single-storey extension into one of more than one storey. To be permitted development, the extension as a whole must go no more than 3 m beyond the rear wall of the original house and stay at least 7 m from the rear boundary, with matching materials and roof pitch. Over a side extension it always needs planning permission, costing £548 (or £575 for applications made from 8 December 2026).

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 Neston (Wiltshire) homes

Matching the roofline

A first-floor extension often changes how the back or side of the house looks more than the original single storey did. Matching the main roof pitch and materials, and keeping the ridge below the main ridge, usually gives the best result and is expected for permitted development in England.

Can the existing structure take it?

Many single-storey extensions were built with foundations, walls and lintels sized for one storey. We find out what is there with trial holes and, where available, the original building control drawings. The engineer then decides whether to reuse, strengthen or rebuild parts of the structure.

How we'd run your project

Understand the brief
At your home in Neston (Wiltshire) we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Design and approvals
We draw the extension and check it against the rules for England, then apply for planning permission or a certificate of lawfulness, whichever fits.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about first-floor extensions in Neston (Wiltshire)

How much does a first-floor extension cost in Neston (Wiltshire)?

Our guide for South West England, which covers Neston (Wiltshire), is £1,850–£2,680 per m² including VAT. A typical project with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £26,000–£37,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Which postcodes do you cover around Neston (Wiltshire)?

We cover Neston (Wiltshire) (SN13) and nearby places including Corsham, Melksham and Chippenham, plus the rest of Wiltshire. The first site visit is free.

Who handles building regulations for a project in Neston (Wiltshire)?

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.

Will the first-floor extension match my house?

It should, and in England matching materials and roof pitch is a condition of permitted development. We match brick, tile, mortar colour and window style where we can, and tell you at the design stage if an exact brick match is not available, so you can choose between the closest match and render or cladding.

What happens to the room below while the first floor is built?

The old roof is removed, so the room below is exposed for a short period. We fit temporary weather protection, plan the work so the roof comes off only when the new structure is ready, and agree with you which rooms will be out of use and for roughly how long.

Nearby

Other towns near Neston (Wiltshire):

Other extensions in Neston (Wiltshire)

All two-storey extension services in Neston (Wiltshire) · First-floor extensions across Wiltshire

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.