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.
From a first conversation about a single-storey extension to the day the site is cleared, homeowners in Isle of Lewis deal with us directly. We come out to measure up at no cost, explain the choices in plain terms and send a written quote. For context, comparable work in Scotland usually falls within £33,500–£72,000 including VAT, and it is available across HS1.
- Guide price
- £33,500–£72,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- HS1
- Planning rules
- Scotland
- Local area
- Eilean Siar
- Survey
- Free, with a written quote
How much does a single-storey extension cost in Isle of Lewis?
Budgeting for a single-storey extension in Isle of Lewis? The numbers below include VAT and are adjusted for Scotland, where costs are about 4% below the national guide. The headline range is £33,500–£72,000. Nothing is final until we have measured up at a free survey and agreed the specification with you.
| Type of job | What it usually involves | Guide in Isle of Lewis |
|---|---|---|
| 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 |
What moves the price up or down:
- Floor area, shape and number of corners
- Roof type, rooflights, lanterns and the amount of glazing
- Ground conditions, foundation depth and drains to divert
- Steelwork needed to open into the existing house
Scope of the work
- Groundworks, foundations and below-ground drainage
- Cavity walls built and insulated to building regulations
- Flat or pitched roof, with rooflights or a lantern if specified
- Windows and external doors, including bifolds if chosen
- Plastering, screed floor and internal doors
- Building control inspections and completion certificate
Homes in Highlands and Islands
Inverness has Victorian villas and terraces and large modern estates, while rural Highland homes range from harled stone cottages and croft houses to modern timber-frame kit houses, which are common across the region. Orkney uses local flagstone, and island and coastal communities mix traditional stone homes with newer bungalows.
Croft houses and stone cottages often need lime harling, re-roofing and window renewal. Bungalows commonly take extensions and loft rooms, and remote projects need careful planning for materials and access.
That variety is why a guide price for a single-storey extension in Isle of Lewis is only a starting point; the survey shows what your particular property needs.
Planning and building rules in Isle of Lewis
Planning law differs across the UK. For a home in Isle of Lewis, it is the Scotland rules below that count, and we check them with the council ahead of any quote.
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
We look at the job
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a single-storey extension.
Your fixed price
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.
Dates and permissions
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
Finish and handover
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
Why homeowners choose us
Questions about a single-storey extension in Isle of Lewis
How long does a single-storey extension take to build?
A single-storey extension usually takes 10–16 weeks on site, from digging foundations to final plastering. Bad weather, deep foundations or a complex roof can add time. Before work starts, allow several weeks for drawings, structural calculations and building control approval, and longer if planning permission is needed. We give you a stage-by-stage programme with your quote so you know what happens each week.
What is the Party Wall Act and does it apply to me?
The Party Wall etc. Act 1996 applies in England and Wales only. In England and Wales, it requires you to give notice to neighbours before certain work on or near a shared wall, such as digging foundations within 3m of their building and deeper than its footings. Neighbours can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act, though general rights still apply. We identify whether notices are needed during the survey.
How much will a single-storey extension cost in Isle of Lewis?
As a guide, expect to pay £33,500–£72,000 including VAT for a single-storey extension in Isle of Lewis. That range is adjusted for Scotland, which runs about 4% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Do you cover Inverness, Nairn and Fort William?
Yes. As well as Isle of Lewis, we cover Inverness, Nairn and Fort William and the rest of Highlands and Islands. 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.
Do I need planning permission for a single-storey extension?
Whether you need planning permission depends on the extension's size and height, how close it is to boundaries, your home's location, whether it is listed or in a conservation area, and which UK nation you live in. In England, many rear extensions up to 3m deep on a semi or terrace, or 4m on a detached house, can be built under permitted development. We check the rules that apply to your home before quoting.
Near Isle of Lewis
Addresses in HS1 are all covered for Isle of Lewis, along with Inverness, Nairn and Fort William close by. Give us your postcode when you get in touch and we will confirm the details.