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 St Andrews?
In St Andrews, 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. Prices in Scotland sit near the national average for this kind of work, and the range for St Andrews reflects that. 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 |
The main things that change the cost:
- Size and layout
- Cladding and finishes
- Access for materials
- Heating type
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a garden annexe in St Andrews?
Here is how the rules work for a garden annexe 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
On a typical garden annexe we handle:
- Foundations and drainage connections
- Insulated walls and roof
- Glazed doors and windows
- Kitchenette and shower room
- Building control sign-off
- Electrics and heating
How long does it take?
Expect 10 to 16 weeks on site. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in St Andrews
Scotland’s housing ranges from sandstone tenements and villas to post-war and modern estates, and the building warrant system shapes how projects are planned.
Projects in St Andrews (KY16) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about garden annexes in St Andrews
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.
How much does a garden annexe cost in St Andrews?
In St Andrews, 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.
How long does it take?
Typically 10 to 16 weeks on site.
Do I need planning permission for a garden annexe in St Andrews?
In Scotland an annexe with living accommodation needs planning permission and a building warrant.
Who approves a garden annexe in St Andrews?
Planning matters in St Andrews go to the council covering your address, and the work needs a building warrant. We prepare and submit the applications for you.
Can it be accessible?
Yes. Level access, wider doors and a wet room can be designed in.