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.
For a homeowner in Fort William, planning a single-storey extension tends to begin with two questions: what will it cost, and how disruptive will it be? Our guide range is £33,500–£72,000 including VAT, and a typical job runs to 10–16 weeks on site. Both numbers firm up once we have seen the property, measured up and agreed exactly what is included.
- Guide price
- £33,500–£72,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- PH33
- Planning rules
- Scotland
- Local area
- Highland
- Survey
- Free, with a written quote
Single-storey extensions prices in Fort William
What will a single-storey extension cost in Fort William? Our guide range is £33,500–£72,000 including VAT. That figure is adjusted for Scotland, about 4% below the national guide, and is intended for planning a budget. A firm written price for your chosen specification follows a free survey at your home.
| Type of job | What it usually involves | Guide in Fort William |
|---|---|---|
| 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 |
Expect these to shape the final quote:
- Floor area, shape and number of corners
- Ground conditions, foundation depth and drains to divert
- Steelwork needed to open into the existing house
- Finishes, kitchen, flooring and heating specification
What do you get?
- Cavity walls built and insulated to building regulations
- Flat or pitched roof, with rooflights or a lantern if specified
- Steel beams to open into the existing house
- Electrics and plumbing by qualified trades, with certificates
- Windows and external doors, including bifolds if chosen
- Plastering, screed floor and internal doors
Building in Fort William
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.
Knowing the typical building types in Highlands and Islands helps, but a survey of your own home in Fort William is what decides the right approach to a single-storey extension.
Planning and building rules in Fort William
The notes below cover Scotland, which is where Fort William sits. Rules change and every property is different, so we speak to the council before pricing your job.
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.
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 single-storey extension so the price reflects your home.
Quote in writing
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.
Plan and prepare
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Fort William property.
Build and hand over
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
Working with SK Home Improvements
Common questions
Can you combine a single-storey extension with other work?
Yes. Because we manage several trades under one contract, we can plan a single-storey extension alongside other work on your Fort William home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
How much will a single-storey extension cost in Fort William?
As a guide, expect to pay £33,500–£72,000 including VAT for a single-storey extension in Fort William. 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 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.
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.
What does a typical extension build look like week by week?
A typical single-storey extension follows the same order: clearing the site and digging foundations, building walls up to roof level, then fitting the roof and windows to make it weathertight. Electrics, plumbing, insulation and plastering follow. The last stage is opening into the house, laying the screed and fitting doors and finishes. Building control inspects at key stages, and we book those visits for you.
Near Fort William
Homes across PH33 in Fort William are within our coverage, as are those in Oban, Inverness and Crieff. If you are just outside these areas, ask anyway, because we work right across the UK.