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 Poole?
In Poole, a garden annexe typically costs £1,850–£2,850 per m² of floor area, including VAT at 20% (standard rate). For a typical 35 m² project that is roughly £65,000–£100,000. Prices in the South West sit near the national average for this kind of work, and the range for Poole reflects that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (24 m²) | £44,500–£68,500 |
| Typical project (35 m²) | £65,000–£100,000 |
| Larger project (49 m²) | £90,500–£139,500 |
| Rate per m² | £1,850–£2,850 |
The main things that change the cost:
- Access for materials
- Heating type
- Drainage connection distance
- Cladding and finishes
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a garden annexe in Poole?
The approval route for Poole is set by planning law 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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
Handled as part of most garden annexes:
- Insulated walls and roof
- Glazed doors and windows
- Foundations and drainage connections
- External cladding or brickwork
- Kitchenette and shower room
- Electrics and heating
How long does it take?
Allow 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 Poole
In parts of the South West, protected landscapes and conservation areas shape what can be built, so materials and roof forms are chosen carefully.
If your home is in Poole or close by in Bournemouth, Christchurch and New Milton, a free home visit is the first step.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed 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 Poole
How much does a garden annexe cost in Poole?
In Poole, a garden annexe typically costs £1,850–£2,850 per m² of floor area, including VAT at 20% (standard rate). A typical 35 m² project comes to roughly £65,000–£100,000. Your fixed price depends on the survey and drawings.
Who approves a garden annexe in Poole?
Planning matters in Poole go to the council covering your address, and the work needs building control approval. 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.
Can an annexe be rented out?
Not without further planning permission, as that would make it a separate dwelling.
How long does it take?
Typically 10 to 16 weeks on site.