Two-storey side extensions in Renfrewshire and Inverclyde

Renfrewshire and Inverclyde at a glance

Nation: Scotland
Price region: Scotland
Postcode areas: PA
Towns covered: 10 listed below, plus surrounding villages
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.
Site visits: Free, no obligation

What a two-storey side extension involves

A two-storey side extension suits a detached or semi-detached house with a side garden, driveway or garage wide enough to build on. You get a design that sits comfortably on the street, a planning application or permitted development check depending on your nation, structural design, a building warrant and the build itself. We manage the whole process, and the work is carried out by vetted teams working under S&K.

Towns in Renfrewshire and Inverclyde include Paisley (PA1), Greenock (PA15), Renfrew (PA4), Johnstone (PA5), Erskine (PA7) and Port Glasgow (PA14). If yours isn't listed, we still cover it.

Guide price in Scotland

Most of the cost of a two-storey side extension is set by its size and specification. For Renfrewshire and Inverclyde 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). Keep a contingency of around 10% for things nobody can see until the ground is opened up.

Spec	Per m²	Typical project
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

Rules in Scotland

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.

There is no Party Wall Act in Scotland. Shared walls and boundaries are governed by title deeds and common law, so we speak to neighbours early and record the condition of shared structures.

Getting the design right

Matching the ridge and roof

A hipped house usually needs a hipped extension roof, and a gabled house a gable. Matching the pitch, tiles, ridge detail and brick bond is what makes a side extension look original rather than added, and councils look closely at it on a front-facing addition.

Avoiding a terracing effect

Where semi-detached houses sit close together, side extensions on neighbouring houses can join up and turn a row of pairs into a terrace. Many councils ask for a gap to the boundary at first floor to stop this, so we check local guidance before fixing the width.

How we work in Renfrewshire and Inverclyde

Free site visit
We visit your home in Renfrewshire and Inverclyde, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Renfrewshire and Inverclyde.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.

Towns we cover in Renfrewshire and Inverclyde

Two-storey side extensions in Renfrewshire and Inverclyde: questions

How much does a two-storey side extension cost in Renfrewshire and Inverclyde?

In 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). Essential and Premium specs move that by roughly 8% down or 20% up.

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.

Will I need planning permission in Renfrewshire and Inverclyde?

Renfrewshire and Inverclyde 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.

Neighbouring areas

All extension services in Renfrewshire and Inverclyde · About two-storey side extensions