Two-storey extensions for detached houses 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 extension for a detached house involves

This service suits you if you own a detached house and want a substantial amount of extra space, whether a side extension over a drive, a rear extension into the garden or a wraparound. You get a survey of the whole plot, options that compare layouts and costs, the approvals your nation needs, structural design and the build, carried out by vetted teams working under S&K.

Across Renfrewshire and Inverclyde we cover Paisley (PA1), Greenock (PA15), Renfrew (PA4), Johnstone (PA5), Erskine (PA7) and Port Glasgow (PA14), plus the smaller places around them.

Guide price in Scotland

A guide price for Renfrewshire and Inverclyde: around £81,000–£108,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). That works out at £1,930–£2,580 per m² of new floor space, including VAT at 20%. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

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 detached house on a large plot may be able to use Class 1B permitted development if no part of the two-storey extension is within 10 m of any boundary, it is no higher than the house and is not in a conservation area. Otherwise a householder application costs £371. A building warrant is needed either way.

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

Larger spans and steelwork

Bigger extensions often mean wider openings and longer spans, which need more steel and sometimes a steel frame. The engineer designs these early, because the size of the steel affects ceiling heights, floor depths and the cost.

Choosing the best side

On a detached house you can often extend on either side or the rear. We look at orientation for daylight, where the stairs and landing are, the distance to each boundary, drains and trees, so the extension goes where it adds the most useful space.

How we work in Renfrewshire and Inverclyde

Start at your house
We come to your home in Renfrewshire and Inverclyde, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Get it approved
Once you're happy with the design we submit it to the council for Renfrewshire and Inverclyde and deal with any questions from the planning officer.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Towns we cover in Renfrewshire and Inverclyde

Two-storey extensions for detached houses in Renfrewshire and Inverclyde: questions

How much does a two-storey extension for a detached house 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.

Is a detached house extension a better investment than moving?

It often costs less than the gap between your house and a larger one nearby, once property tax, legal fees and removal costs are counted, but that depends on your area. Extending also has limits: every street has a ceiling price. We give you build costs so you can compare them with local asking prices.

Can I extend a detached house on both sides?

Sometimes. With planning permission, a council may accept extensions on both sides if the house stays well proportioned and keeps gaps to the boundaries. It is more common to extend on one side and the rear, or with a wraparound. We look at the plot as a whole before suggesting more than one extension.

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 extensions for detached houses