What is a garden annexe?

A garden annexe is a single-storey building in the garden with its own living space, bathroom and often a kitchenette, used by relatives, older children or guests. Unlike a garden room, it is built as habitable accommodation with foundations, insulation and services.
How much does a garden annexe cost in Largs?
In Largs, a garden annexe typically costs £1,750–£2,700 per m² of floor area, including VAT at 20% (standard rate). For a typical 35 m² project that is roughly £61,000–£94,500. Building costs in Scotland are close to the UK average, so the figures for Largs are close to our national guide. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (24 m²) | £42,000–£65,000 |
| Typical project (35 m²) | £61,000–£94,500 |
| Larger project (49 m²) | £86,000–£132,500 |
| Rate per m² | £1,750–£2,700 |
Your quote will depend mainly on:
- Access for materials
- Heating type
- Size and layout
- Cladding and finishes
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a garden annexe in Largs?
The approval route for Largs is set by planning law in Scotland. In Scotland an annexe with living accommodation needs planning permission and a building warrant.
In Scotland a building warrant is needed before work starts on most extensions, loft conversions and conversions. It is issued by the council’s building standards service. When the work is finished, a completion certificate is submitted and accepted by the council after inspection.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
Handled as part of most garden annexes:
- Foundations and drainage connections
- Glazed doors and windows
- Kitchenette and shower room
- Insulated walls and roof
- Planning drawings and application
- Building control sign-off
How long does it take?
Expect 10 to 16 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Largs
In Scotland, bungalows and one-and-a-half-storey homes are common, so dormer conversions are a popular way to add bedrooms.
From KA30 outwards, we take on projects throughout Largs and the surrounding parts of Ayrshire.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about garden annexes in Largs
Does it need building regulations?
Yes, as it contains sleeping accommodation and services.
Do I need planning permission for a garden annexe in Largs?
In Scotland an annexe with living accommodation needs planning permission and a building warrant.
How much does a garden annexe cost in Largs?
In Largs, a garden annexe typically costs £1,750–£2,700 per m² of floor area, including VAT at 20% (standard rate). A typical 35 m² project comes to roughly £61,000–£94,500. Your fixed price depends on the survey and drawings.
Will council tax apply?
Annexes can be banded separately, though discounts or exemptions apply in some cases when occupied by family. Check with your council.
Do you build garden annexes in Largs?
Yes. We build garden annexes across Largs, including postcodes KA30. Every project starts with a free home visit.
Can an annexe be rented out?
Not without further planning permission, as that would make it a separate dwelling.
