Two-storey annexe extensions in Lanarkshire

Lanarkshire at a glance

Nation: Scotland
Price region: Scotland
Postcode areas: G, ML
Towns covered: 27 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 annexe extension involves

This service suits you if a parent, grown-up child or carer is moving in and you want them to have their own space while staying connected to the house. You get a layout that can be self-contained or shared, the approvals your nation needs with the annexe use made clear, accessible design where needed and the build, carried out by vetted teams working under S&K.

The main places we list in Lanarkshire are East Kilbride (G74), Hamilton (ML3), Cumbernauld (G67), Coatbridge (ML5), Airdrie (ML6) and Motherwell (ML1). We cover the villages in between too.

Guide price in Scotland

Most of the cost of a two-storey annexe extension is set by its size and specification. For Lanarkshire and the rest of Scotland, our guide is £1,930–£2,580 per m² including VAT, so about £81,000–£108,500 (plus kitchenette and shower room fittings, priced to your choice) for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Design fees, structural calculations and approval fees are separate and listed on our prices page.

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 annexe extension needs to be at least 10 m from every boundary to be permitted development under Class 1B, so most need a householder application (£371, decided within two months). The building warrant covers fire safety and escape for the self-contained layout.

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

Services and metering

An annexe usually shares the main house's water, gas and electricity, with a separate circuit or sub-meter if you want to split costs. We plan heating, hot water and drainage so the annexe works well without needing new supplies.

Annexe, not a separate house

To stay an annexe, the space should be used by members of the household and stay linked to the main house, usually with an internal door and shared address, garden and services. Designing it as a fully separate home can mean the council treats it as a new dwelling.

How we work in Lanarkshire

Look at the house
We start in Lanarkshire with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Get it approved
Once you're happy with the design we submit it to the council for Lanarkshire 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.
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 Lanarkshire

Two-storey annexe extensions in Lanarkshire: questions

How much does a two-storey annexe extension cost in Lanarkshire?

In Scotland our guide is £1,930–£2,580 per m² including VAT, so about £81,000–£108,500 (plus kitchenette and shower room fittings, priced to your choice) 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 rent out an annexe later?

Not always. Many annexe permissions include a condition that it is only used by members of the household, so renting it out may need a fresh planning application. If you think you might want to let it, tell us at the start so we can explain the options.

Can an annexe be designed for someone with limited mobility?

Yes. We can plan a ground-floor bedroom space, a level-access shower, wider doorways, lever handles and space for a stairlift later. These features are much cheaper to build in at the start than to add afterwards, and they keep the annexe useful as needs change.

Can an annexe have its own front door?

It can, but a separate front door, kitchen and address together make it look more like a separate home, which can change how the council treats it for planning. Many annexes have their own door to the garden or side and an internal door to the main house. We explain how each choice is likely to be viewed before the design is fixed.

Will I need planning permission in Lanarkshire?

Lanarkshire 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 Lanarkshire · About two-storey annexe extensions