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 Bedfordshire?
In Bedfordshire, a garden annexe typically costs £1,900–£2,950 per m² of floor area, including VAT at 20% (standard rate). For a typical 35 m² project that is roughly £66,500–£103,000. Building costs in the East of England run about 6% above the UK average, and the figures for Bedfordshire are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (24 m²) | £45,500–£71,000 |
| Typical project (35 m²) | £66,500–£103,000 |
| Larger project (49 m²) | £93,000–£144,500 |
| Rate per m² | £1,900–£2,950 |
The biggest cost drivers are:
- Access for materials
- Heating type
- Drainage connection distance
- Kitchen and bathroom
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a garden annexe in Bedfordshire?
Whether you need planning permission depends on your house and its location in England. In England an annexe used as living accommodation usually needs planning permission. Outbuildings built under permitted development must be incidental to the house, such as a gym or office, not a bedroom.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
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:
- External cladding or brickwork
- Kitchenette and shower room
- Glazed doors and windows
- Foundations and drainage connections
- Planning drawings and application
- Building control sign-off
How long does it take?
The build itself usually takes 10 to 16 weeks on site. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Bedfordshire
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
Towns we cover in Bedfordshire include Luton, Bedford, Dunstable, Leighton Buzzard, Ampthill and Kempston Hardwick.
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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about garden annexes in Bedfordshire
Does a garden annexe need planning permission?
Usually yes if it is used as living accommodation. Outbuildings under permitted development must be incidental to the house, such as a gym or office, not bedrooms.
Does it need building regulations?
Yes, as it contains sleeping accommodation and services.
Can it be accessible?
Yes. Level access, wider doors and a wet room can be designed in.
How much does a garden annexe cost in Bedfordshire?
In Bedfordshire, a garden annexe typically costs £1,900–£2,950 per m² of floor area, including VAT at 20% (standard rate). A typical 35 m² project comes to roughly £66,500–£103,000. Your fixed price depends on the survey and drawings.
Do you build garden annexes in Bedfordshire?
Yes. We build garden annexes across Bedfordshire, including postcodes LU1, LU2, LU3, LU4 and LU5. Every project starts with a free home visit.