A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
Cumbernauld sits within our coverage for a double-storey extension, as do neighbouring Airdrie, Coatbridge and Kirkintilloch. Before giving a price we want to see the property: the condition of what's there now, the access, and anything that might need extra work. The guide range for Scotland is £58,000–£115,000 including VAT, and your written quote will spell out exactly what that covers.
- Guide price
- £58,000–£115,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- G67
- Planning rules
- Scotland
- Local area
- North Lanarkshire
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Cumbernauld?
Prices for a double-storey extension vary from house to house, but in Cumbernauld most projects fall within £58,000–£115,000 including VAT. That reflects costs in Scotland, about 4% below the national guide. Treat the table as a budgeting aid; the written figure follows a survey we carry out for free.
| Type of job | What it usually involves | Guide in Cumbernauld |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £38,500–£62,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £58,000–£115,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £96,000–£173,000 |
What moves the price up or down:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Foundation depth, ground conditions and drains to divert
What’s included?
- Groundworks, foundations and below-ground drainage
- Insulated cavity walls with brick or render to match the house
- Roof structure tied into the existing roof, tiled to match
- Scaffolding for the full build, erected and inspected
- Electrics, plumbing and heating by qualified trades, with certificates
- Building control inspections and completion certificate
Building in Cumbernauld
Lanarkshire mixes sandstone tenements and terraces in Hamilton, Motherwell, Airdrie and Coatbridge with former miners' rows and large post-war estates, many finished in roughcast. East Kilbride and Cumbernauld were developed as post-war new towns, and newer private estates surround most towns.
Roughcast homes commonly need re-rendering, window replacement and roof work. Semis and bungalows suit extensions and loft conversions, and new-town houses often take garage conversions and driveways.
For a double-storey extension in Cumbernauld, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Planning and building rules in Cumbernauld
Because Cumbernauld falls under Scotland's rules, the guidance below is the version relevant to you. Before sending a price, we check your property's position with the council.
In Scotland, extensions of more than one storey are only permitted development in narrow cases (Class 1B, well away from the boundary they face and outside conservation areas), so most need planning permission.
A building warrant is required before work starts. Scotland has no Party Wall Act; neighbour and title issues are handled under general law.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Survey and measure
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a double-storey extension so the price reflects your home.
Price and scope agreed
After the survey we send a quote for a double-storey extension that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Plan and prepare
Before anyone starts, we confirm the programme in writing, check whether consents are required and arrange deliveries. If a skip or scaffolding on the road needs a permit, we apply for it.
The work itself
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
Working with SK Home Improvements
Frequently asked questions
Do you cover Airdrie, Coatbridge and Kirkintilloch?
Yes. As well as Cumbernauld, we cover Airdrie, Coatbridge and Kirkintilloch and the rest of Lanarkshire. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Can we live at home while it is built?
Most families stay at home during a double-storey extension. The new structure is built outside first, and we only break through into the existing rooms near the end, usually one floor at a time. Upstairs, this may mean a bedroom is out of use for a week or two. We fit dust screens, protect floors and stairs, and plan any time without water or power in advance.
How long does a double-storey extension take?
A double-storey extension typically takes 14–22 weeks on site, depending on size, roof design and weather. Foundations and ground-floor walls come first, then the first-floor joists, upper walls and roof. Once it is weathertight, electrics, plumbing, plastering and finishes follow. Allow extra time beforehand for drawings, calculations and approvals. We give you a stage-by-stage programme with your quote.
Do I need planning permission in Cumbernauld?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Cumbernauld is in Scotland, so Scotland's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
Is a double-storey extension better value than single-storey?
A double-storey extension usually gives better value per square metre than a single-storey one, because the same foundations and roof serve twice the floor area. The overall cost is higher, and planning can be harder because of the effect on neighbours. If you might want an extra bedroom later, building both floors now avoids a second round of disruption and scaffolding.
Also covering areas around Cumbernauld
Coverage for Cumbernauld spans G67. Close by, Airdrie, Coatbridge and Kirkintilloch are covered too, and the rest of our UK-wide area follows the same survey-then-quote process from start to finish.