Two-storey side extensions in Renfrew

Renfrew: the key facts for this kind of project.

Postcode districts: PA4
County / area: Renfrewshire and Inverclyde, Scotland
Price region: Scotland
Guide price: £81,000–£108,500 (£1,930–£2,580 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: Clydebank (2.1 miles), Erskine (3 miles), Dalmuir (3 miles)
Distance to Paisley: about 3.2 miles
First visit: Free, no obligation

About a two-storey side extension

A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.

We cover Renfrew (PA4) and the places around it, including Clydebank (2.1 miles), Erskine (3.0 miles) and Dalmuir.

What it costs in Renfrew

Most of the cost of a two-storey side extension is set by its size and specification. For Renfrew and the rest of Scotland, our guide is £1,930–£2,580 per m² including VAT, so about £81,000–£108,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Professional fees for drawings and the structural engineer are listed separately on our prices page.

Spec	Per m²	A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential	£1,770–£2,380 per m²	£74,500–£100,000
Standard	£1,930–£2,580 per m²	£81,000–£108,500
Premium	£2,310–£3,100 per m²	£97,000–£130,500

Planning and building standards in Renfrew

In Scotland, a two-storey side extension is only permitted development under Class 1B if no part is within 10 m of any boundary and it is not on an elevation fronting a road. Side extensions rarely meet this, so plan for a householder application (£371, decided within two months) and a building warrant from the council 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 Renfrew homes

Access and services

Side extensions often cover the only route to the back garden, a gas meter, soil pipes or a drain run. We plan bin and bike access, move meters and pipes where needed and check drains early, because these items affect both cost and layout.

Side windows, boundaries and gutters

Upstairs windows in the side wall face the neighbour, so they are usually obscure-glazed and fixed, or left out. Building close to the boundary also raises questions about foundations, overhanging gutters and access for maintenance, so we design the eaves and gutter to stay within your land.

How we'd run your project

Start at your house
We come to your home in Renfrew, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in Scotland before drawing in detail.
Detail and price
Construction drawings, engineer's calculations and building warrant approval, then a written fixed price for the build.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Questions about two-storey side extensions in Renfrew

Which postcodes do you cover around Renfrew?

We cover Renfrew (PA4) and nearby places including Clydebank, Erskine and Dalmuir, plus the rest of Renfrewshire and Inverclyde. The first site visit is free.

How much does a two-storey side extension cost in Renfrew?

Our guide for Scotland, which covers Renfrew, is £1,930–£2,580 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £81,000–£108,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

Who handles building standards for a project in Renfrew?

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 long does a two-storey side extension take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils have two months to decide a local planning application), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.

Can I build a two-storey side extension over my driveway?

Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.

Nearby

Close to Renfrew? We work across the area, including:

Other extensions in Renfrew

All two-storey extension services in Renfrew · Two-storey side extensions across Renfrewshire and Inverclyde

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