First-floor extensions in Stratford-upon-Avon

The basics for Stratford-upon-Avon at a glance.

Postcode districts: B49, B50, CV36 and CV37
County / area: Warwickshire, England
Price region: West Midlands
Guide price: £25,000–£36,500 (£1,800–£2,600 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: Warwick (8.2 miles), Leamington Spa (10.2 miles), Kenilworth (12.1 miles)
Distance to Nuneaton: about 25.1 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.

We cover postcode districts B49, B50, CV36 and CV37 in and around Stratford-upon-Avon, along with neighbouring Warwick, Leamington Spa and Kenilworth.

What it costs in Stratford-upon-Avon

Guide prices for first-floor extensions in the West Midlands are around £1,800–£2,600 per m² of new floor space, including VAT. For a typical project with 4 m × 3.5 m of new first-floor space (14 m²), that's roughly £25,000–£36,500. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

Spec	Per m²	4 m × 3.5 m of new first-floor space (14 m²)
Essential	£1,660–£2,390 per m²	£23,000–£33,500
Standard	£1,800–£2,600 per m²	£25,000–£36,500
Premium	£2,160–£3,120 per m²	£30,000–£43,500

Planning and building regulations in Stratford-upon-Avon

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 Stratford-upon-Avon homes

Escape and fire safety

A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and 450 mm high, with the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs.

Replacing the flat roof

The existing roof usually comes off and is replaced by a new first-floor structure. The room below is exposed for a short time, so we plan temporary weatherproofing and sequence the work to keep the kitchen or living room usable for as long as possible.

How we'd run your project

Free site visit
We visit your home in Stratford-upon-Avon, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Questions about first-floor extensions in Stratford-upon-Avon

How much does a first-floor extension cost in Stratford-upon-Avon?

Our guide for the West Midlands, which covers Stratford-upon-Avon, is £1,800–£2,600 per m² including VAT. A typical project with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £25,000–£36,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Do I need planning permission for a first-floor extension in Stratford-upon-Avon?

Stratford-upon-Avon is in England, so England planning rules apply. 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. 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 Stratford-upon-Avon?

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.

Can I build on top of my existing single-storey extension?

Often yes, but only after the structure has been checked. Foundations, walls and lintels built for one storey may not carry two. We dig trial holes, look for the original building control approval and ask the structural engineer to confirm what can stay, what needs strengthening and what must be rebuilt.

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

Close to Stratford-upon-Avon? We work across the area, including:

Other extensions in Stratford-upon-Avon

All two-storey extension services in Stratford-upon-Avon · First-floor extensions across Warwickshire

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Stratford-upon-Avon.