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 Ealing?
In Ealing, a garden annexe typically costs £2,350–£3,650 per m² of floor area, including VAT at 20% (standard rate). For a typical 35 m² project that is roughly £82,000–£128,000. Building costs in London run about 30% above the UK average, and the figures for Ealing are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (24 m²) | £56,500–£87,500 |
| Typical project (35 m²) | £82,000–£128,000 |
| Larger project (49 m²) | £115,000–£179,000 |
| Rate per m² | £2,350–£3,650 |
Your quote will depend mainly on:
- Heating type
- Access for materials
- Cladding and finishes
- Drainage connection distance
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 Ealing?
The approval route for Ealing 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.
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:
- Glazed doors and windows
- Building control sign-off
- Planning drawings and application
- External cladding or brickwork
- Foundations and drainage connections
- Insulated walls and roof
How long does it take?
Build time is typically 10 to 16 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Ealing
Many London boroughs have conservation areas and detailed design guides, so early design advice saves time at the planning stage.
If your home is in Ealing or close by in Southall, Greenford and Hayes, 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
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about garden annexes in Ealing
Do you build garden annexes in Ealing?
Yes. We build garden annexes across Ealing, including postcodes UB18, W5 and W13. Every project starts with a free home visit.
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 long does it take?
Typically 10 to 16 weeks on site.
How much does a garden annexe cost in Ealing?
In Ealing, a garden annexe typically costs £2,350–£3,650 per m² of floor area, including VAT at 20% (standard rate). A typical 35 m² project comes to roughly £82,000–£128,000. Your fixed price depends on the survey and drawings.
Can an annexe be rented out?
Not without further planning permission, as that would make it a separate dwelling.