A single-storey extension is a new ground-floor room built onto your house, usually at the rear or side, with its own foundations, walls and roof, creating a bigger kitchen, living space or bedroom without moving home.
Argyll and Bute is part of our UK-wide coverage for a single-storey extension. Places we cover include Helensburgh, Dunoon, Oban and Isle of Bute, and we travel to smaller communities across the area as well. Since your property is in Scotland, the relevant planning and building rules are the ones set there. In Scotland, budget around £33,500–£72,000 with VAT; the figure is confirmed after a survey that costs you nothing.
- Guide price
- £33,500–£72,000 inc VAT
- Time on site
- 10–16 weeks on site
- Planning rules
- Scotland
- Price level
- About 4% below the national guide
- Towns listed
- 4
- Survey
- Free, with a written quote
Single-storey extensions prices in Argyll and Bute
No two jobs cost exactly the same, but the ranges below give a fair picture of a single-storey extension in Argyll and Bute. Pricing for Scotland runs about 4% below the national guide, and the overall guide is £33,500–£72,000 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in Argyll and Bute |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £21,000–£38,500 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £33,500–£72,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £67,000–£125,000 |
Your price depends mostly on:
- Floor area, shape and number of corners
- Roof type, rooflights, lanterns and the amount of glazing
- Ground conditions, foundation depth and drains to divert
- Finishes, kitchen, flooring and heating specification
Scope of the work
- Groundworks, foundations and below-ground drainage
- Cavity walls built and insulated to building regulations
- Steel beams to open into the existing house
- Electrics and plumbing by qualified trades, with certificates
- Windows and external doors, including bifolds if chosen
- Building control inspections and completion certificate
Homes in Argyll and Bute
Much of Argyll and Bute is rural and coastal, with whitewashed or harled stone cottages, slate roofs and island homes. Helensburgh has Victorian villas, Oban, Dunoon and Rothesay have Victorian seaside terraces, and post-war and newer housing surrounds the main towns.
Stone cottages need lime harling, repointing and slate roof repairs; villas may need roof and window renewal. Island and remote properties need the programme planned around ferries, deliveries and weather.
One of the wettest and windiest parts of the UK, with high exposure on the coast and islands, so roof and render details must suit severe weather.
Do you need permission in Argyll and Bute?
England, Wales, Scotland and Northern Ireland each handle planning a little differently. Argyll and Bute comes under Scotland, covered below, and we raise any questions with the council before your quote is finalised.
In Scotland, Class 1A permitted development covers some single-storey extensions, within limits on depth, height and distance from boundaries, and not in conservation areas or on flats. Anything outside those limits needs planning permission from the council.
A building warrant from the council’s building standards service is usually needed before work starts, and a completion certificate is accepted at the end. There is no Party Wall Act in Scotland; work near a boundary is agreed with neighbours under general law.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
The four stages
Free site survey
First, someone visits your home in Argyll and Bute to see the space, take measurements and note anything that could affect the work, such as access or the condition of what is there. There is no charge for this visit.
Price and scope agreed
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Getting ready
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
Finish and handover
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
How we work
Questions about a single-storey extension in Argyll and Bute
How much does a single-storey extension cost?
A typical single-storey rear extension of 15–25m² costs £33,500–£72,000, built to a plastered finish ready for your kitchen and decoration. As a guide, allow roughly £1,600–£2,800 per square metre plus fixed costs for groundworks, steelwork and fees. Smaller extensions cost more per square metre. The kitchen, flooring and large glazed doors are usually the biggest extras. We confirm a fixed price for the agreed specification after the survey.
How long will a single-storey extension take?
On a typical home, allow 10–16 weeks on site. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
Do I need an architect for an extension?
You need proper drawings for an extension, but not always a full architect service. A designer or architectural technician can produce planning and building regulations drawings, and a structural engineer provides beam and foundation calculations. If you already have drawings, we price from them. If not, we can arrange the drawings and calculations as part of the project so everything is coordinated from the start.
Is a flat roof or a pitched roof better on an extension?
A flat roof is quicker to build and usually costs less, gives a clean modern look and works well with a roof lantern. A pitched roof matches the main house, sheds water faster and allows a vaulted ceiling, but it costs more and its height can affect neighbours. Modern flat roofs in EPDM rubber or GRP last well when properly detailed. Planning rules on height can also decide the choice.
Do I need planning permission in Argyll and Bute?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Argyll and Bute 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.
Towns in Argyll and Bute
Below is our list of Argyll and Bute towns for a single-storey extension. If yours isn't shown, we may still cover it, so it is worth asking us directly.