Single-storey rear extensions in Cumbernauld: design, approvals and build
Cumbernauld homeowners can use us for the whole single-storey extension project: survey, design, planning or permitted development checks, the building warrant and the build itself.
- Guide price in CumbernauldFrom £20,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Build time10–16 weeks on site
- Postcode districtsG65, G67, G68
Local to Cumbernauld
Site visits are available across Cumbernauld (G65, G67, G68). Neighbouring towns we cover include Airdrie (6 miles), Coatbridge (6 miles), Bellshill (9 miles), Motherwell (11 miles).
Kirkintilloch, in Dunbartonshire, is roughly 6 miles from Cumbernauld and also on our list. Across Scotland, extensions follow Scottish planning and building standards, including the building warrant process, which we build into the programme from the start.
Guide prices for Cumbernauld
Labour and material costs vary across the UK, so for Cumbernauld we use our Scotland factor (×0.98). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Cumbernauld: £1,720 to £3,330 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £20,500 – £24,500 | £24,000 – £31,000 | £30,500 – £40,000 |
| 4 m × 5 m 20 m² | £34,000 – £40,500 | £40,000 – £51,000 | £50,500 – £67,000 |
| 5 m × 6 m 30 m² | £51,000 – £60,500 | £60,000 – £76,500 | £76,000 – £100,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Will the council need to approve it?
In Scotland, householder permitted development rules (Class 1A for single-storey ground-floor extensions and Class 1B for extensions of more than one storey) allow some smaller extensions without a planning application, within limits on depth, height and distance from the boundary. Conservation areas and listed buildings are more restricted. Separately, almost every extension needs a building warrant from the council before work starts.
Homes in conservation areas, national scenic areas and listed buildings have tighter rules, so we always check the property's status and planning history before design starts.
Building close to a public sewer needs the agreement of Scottish Water, which we check during design.
Applications are decided by your council as planning authority.
Included in a typical project
- Planning route checked and the right approval obtained
- Foundations, drainage and groundworks
- Flat or pitched roof, rooflights or lantern
- Doors, windows, insulation, plastering and first fix to finish
- Building regulations drawings and structural calculations
- Walls, steel beams and the new opening into the house
Depth is the big decision. Every extra metre adds floor area but also takes garden and can push you out of permitted development. We draw the room at two or three depths so you can see the trade-off in space, light and cost before anything is fixed.
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Single-storey extension questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Cumbernauld, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do you cover all of Cumbernauld?
Yes. We cover Cumbernauld and the surrounding parts of Lanarkshire. Site visits are free and there is no obligation.
Who do I contract with for a single-storey extension in Cumbernauld?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Flat roof or pitched roof?
Flat roofs give more headroom inside and suit lanterns and rooflights; pitched roofs can blend better with older houses. Both meet building regulations when built properly. See our flat roof and pitched roof pages for the details.
How much does a single-storey extension cost per square metre?
Our guide range is about £1,720 to £3,330 per m² including VAT, depending on specification. A standard-spec 4 m × 5 m room usually lands at £40,000 to £51,000 in Cumbernauld, plus design and council fees.
Book a free site visit in Cumbernauld
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.