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 Didcot?
In Didcot, a garden annexe typically costs £2,000–£3,150 per m² of floor area, including VAT at 20% (standard rate). For a typical 35 m² project that is roughly £70,000–£110,000. Prices across the South East are typically 12% above the UK average for this kind of work, which is reflected in the range for Didcot. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (24 m²) | £48,000–£75,500 |
| Typical project (35 m²) | £70,000–£110,000 |
| Larger project (49 m²) | £98,000–£154,500 |
| Rate per m² | £2,000–£3,150 |
What moves the price most:
- Heating type
- Size and layout
- Access for materials
- Cladding and finishes
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 Didcot?
Here is how the rules work for a garden annexe 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
From survey to sign-off, the job normally involves:
- Kitchenette and shower room
- External cladding or brickwork
- Glazed doors and windows
- Electrics and heating
- Planning drawings and application
- 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 Didcot
Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.
We work across Didcot and neighbouring areas such as Abingdon, Oxford and Thatcham. Postcodes we cover in Didcot include OX11.
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
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about garden annexes in Didcot
How much does a garden annexe cost in Didcot?
In Didcot, a garden annexe typically costs £2,000–£3,150 per m² of floor area, including VAT at 20% (standard rate). A typical 35 m² project comes to roughly £70,000–£110,000. Your fixed price depends on the survey and drawings.
Can it be accessible?
Yes. Level access, wider doors and a wet room can be designed in.
Do you build garden annexes in Didcot?
Yes. We build garden annexes across Didcot, including postcodes OX11. Every project starts with a free home visit.
How long does it take?
Typically 10 to 16 weeks on site.
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.