First-floor extensions in St Andrews

Before you start in St Andrews, here's what applies.

Postcode districts: KY10 and KY16
County / area: Fife, Scotland
Price region: Scotland
Guide price: £23,500–£34,000 (£1,690–£2,440 per m²)
Approval route: Planning permission is usually needed: Class 1B permitted development only applies if every part of the extension is at least 10 m from all boundaries. A building warrant is needed before work starts.
Nearest towns: Cupar (8.3 miles), Monifieth (9.9 miles), Dundee (11.2 miles)
Distance to Dunfermline: about 31.4 miles
First visit: Free, no obligation

About a first-floor extension

A first-floor extension is a new upstairs room built on top of an existing single-storey part of your house, such as a rear kitchen extension, a utility or a side annexe. It adds a bedroom, bathroom or study without enlarging the footprint. Whether it works depends mainly on whether the walls and foundations below can carry the extra load.

We cover St Andrews (KY10 and KY16) and the places around it, including Cupar (8.3 miles), Monifieth (9.9 miles) and Dundee.

What it costs in St Andrews

Our guide for Scotland is £1,690–£2,440 per m² including VAT. On a project with 4 m × 3.5 m of new first-floor space (14 m²), that puts a first-floor extension in St Andrews at roughly £23,500–£34,000. 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	£1,560–£2,250 per m²	£22,000–£31,500
Standard	£1,690–£2,440 per m²	£23,500–£34,000
Premium	£2,030–£2,930 per m²	£28,500–£41,000

Planning and building standards in St Andrews

In Scotland, permitted development for extensions of more than one storey (Class 1B) needs at least 10 m to every boundary and no part higher than the house. Most first-floor extensions cannot meet the 10 m test, so plan for a householder application (£371, decided within two months) and a building warrant before work starts.

Approval in Scotland: Householder planning application: £371. Councils have two months to decide a local planning application.

Building standards: A building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks.

Design points for St Andrews homes

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.

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 standards drawings. The engineer then decides whether to reuse, strengthen or rebuild parts of the structure.

How we'd run your project

Look at the house
We start in St Andrews with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Drawings, then consent
We draw the scheme, check it against the rules in Scotland, and take it through the right consent with the council.
Structure and building standards
A structural engineer sizes the foundations and steels, and we get a building warrant before work starts.
Finish and certify
Second fix, plastering and making good, then the council's final building standards inspection and the completion paperwork.

Questions about first-floor extensions in St Andrews

Who handles building standards for a project in St Andrews?

We handle it as part of the project. What's needed in Scotland: a building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

Do I need planning permission for a first-floor extension in St Andrews?

St Andrews is in Scotland. Planning permission is usually needed: Class 1B permitted development only applies if every part of the extension is at least 10 m from all boundaries. A building warrant is needed before work starts.

How much does a first-floor extension cost in St Andrews?

Our guide for Scotland, which covers St Andrews, is £1,690–£2,440 per m² including VAT. A typical project with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £23,500–£34,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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 a building warrant 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

We also cover places near St Andrews, including:

Other extensions in St Andrews

All two-storey extension services in St Andrews · First-floor extensions across Fife

The quickest next step is a visit. We'll look at your house in St Andrews and give you an honest view of the options.