First-floor extensions in Elderslie
For a first-floor extension in Elderslie, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Renfrewshire and Inverclyde.
The basics for Elderslie at a glance.
- Postcode districts
- PA5
- County / area
- Renfrewshire and Inverclyde, 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
- Linwood (1.1 miles), Johnstone (1.2 miles), Paisley (2.1 miles)
- Distance to Paisley
- about 2.1 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, a building warrant and the build, managed by us and carried out by vetted teams working under S&K.
Around Elderslie we also work in Linwood, Johnstone and Paisley, and across the rest of Renfrewshire and Inverclyde. Postcode district in and near Elderslie: PA5.
What it costs in Elderslie
Expect a first-floor extension in Elderslie to land somewhere around £23,500–£34,000 for 4 m × 3.5 m of new first-floor space (14 m²). Our Scotland guide rate is £1,690–£2,440 per m², including VAT. Design fees, structural calculations and approval fees are separate and listed on our prices page.
| 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 Elderslie
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 Elderslie 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.
Tying into the house
The new floor and walls must line up with the existing first floor, often through a new opening in the rear wall above the old one. Floor levels, the position of upstairs windows and the existing roof all affect where the opening can go, so we survey both floors carefully.
How we'd run your project
Visit and first ideas
One of our team visits your house in Elderslie, checks the walls, roof and drains, and sketches out options with you.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in Scotland before drawing in detail.
Structure and building standards
A structural engineer sizes the foundations and steels, and we get a building warrant before work starts.
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 Elderslie
Who handles building standards for a project in Elderslie?
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.
How much does a first-floor extension cost in Elderslie?
Our guide for Scotland, which covers Elderslie, 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.
Which postcodes do you cover around Elderslie?
We cover Elderslie (PA5) and nearby places including Linwood, Johnstone and Paisley, plus the rest of Renfrewshire and Inverclyde. The first site visit is free.
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
Other towns near Elderslie:
Other extensions in Elderslie
- Rear
- Side
- Wraparound
- Part two-storey
- Over a garage
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Elderslie · First-floor extensions across Renfrewshire and Inverclyde
Want a figure first? Try our guide price tool, then book a free visit to firm it up.