Two-storey front extensions in Wiltshire

Wiltshire at a glance

Nation: England
Price region: South West England
Postcode areas: BA, SN, SP
Towns covered: 14 listed below, plus surrounding villages
Approval route: Planning permission is needed: nothing can go forward of the front wall under permitted development.
Site visits: Free, no obligation

What a two-storey front extension involves

A two-storey front extension is an addition built forward of the front wall of your house on both floors, often a deeper hall or study below and a larger bedroom above. Because it changes how the house looks from the street, it always needs planning permission in England and is judged closely on design. It suits houses set well back from the road.

The main places we list in Wiltshire are Swindon (SN1), Salisbury (SP1), Trowbridge (BA14), Chippenham (SN15), Melksham (SN12) and Warminster (BA12). We cover the villages in between too.

Guide price in South West England

Using our South West England rates, a two-storey front extension with a 3 m × 2 m footprint on two floors (12 m² of new floor space) comes to about £27,000–£37,000, including VAT. Bigger or more glazed designs cost more per m². Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

Spec	Per m²	Typical project
Essential	£2,080–£2,840 per m²	£25,000–£34,000
Standard	£2,270–£3,090 per m²	£27,000–£37,000
Premium	£2,720–£3,710 per m²	£32,500–£44,500

Rules in England

In England, a two-storey front extension always needs householder planning permission, because permitted development does not allow any extension forward of the principal elevation. The fee is £548 (or £575 for applications made from 8 December 2026). Councils judge it mainly on design and the street scene, 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.

The Party Wall etc. Act 1996 applies, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

Roof and gable design

A front extension is the most visible part of the house, so the roof needs to look deliberate: a matching gable, a hipped bay or a porch roof below a first-floor bay. We match the pitch and materials and keep the ridge below the main roof.

Daylight to existing rooms

A front extension can make the hall and front rooms darker, especially if it covers an existing window. We position new windows to keep the house bright, and check that the new front bedroom gets good daylight without overlooking houses opposite.

How we work in Wiltshire

Visit and first ideas
One of our team visits your house in Wiltshire, checks the walls, roof and drains, and sketches out options with you.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Towns we cover in Wiltshire

Two-storey front extensions in Wiltshire: questions

How much does a two-storey front extension cost in Wiltshire?

In South West England our guide is £2,270–£3,090 per m² including VAT, so about £27,000–£37,000 for a 3 m × 2 m footprint on two floors (12 m² of new floor space). Essential and Premium specs move that by roughly 8% down or 20% up.

Can I combine a front extension with a porch?

Yes. A common approach is a two-storey bay or gable with a single-storey porch roof running across the front door. This gives a bigger hall and front bedroom while breaking up the mass of the front wall. Both parts are covered by the same planning application and building regulations approval.

How far forward can a front extension go?

There is no fixed figure, because a two-storey front extension needs planning permission and the council decides case by case. Many councils' design guides favour a shallow projection that keeps a clear front garden. Our guide prices assume a modest example with a 3 m × 2 m footprint on two floors (12 m² of new floor space).

Will the council approve a two-storey front extension?

It depends on the street. Councils are more cautious about front extensions than rear ones because they change the street scene. Approval is more likely where the house is set back, the projection is modest, the design echoes the original house and similar additions already exist nearby. We give you a frank view at the free site visit.

Will I need planning permission in Wiltshire?

Wiltshire is in England. Planning permission is needed: nothing can go forward of the front wall under permitted development.

Neighbouring areas

All extension services in Wiltshire · About two-storey front extensions