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 Sunderland?
In Sunderland, a garden annexe typically costs £1,600–£2,500 per m² of floor area, including VAT at 20% (standard rate). For a typical 35 m² project that is roughly £56,000–£87,500. The guide for Sunderland reflects typical costs in the North East, roughly 10% below the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (24 m²) | £38,500–£60,000 |
| Typical project (35 m²) | £56,000–£87,500 |
| Larger project (49 m²) | £78,500–£122,500 |
| Rate per m² | £1,600–£2,500 |
The biggest cost drivers are:
- Cladding and finishes
- Access for materials
- Kitchen and bathroom
- Size and layout
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 Sunderland?
The approval route for Sunderland 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
What we take care of:
- Glazed doors and windows
- Electrics and heating
- Building control sign-off
- Kitchenette and shower room
- Insulated walls and roof
- External cladding or brickwork
How long does it take?
Expect 10 to 16 weeks on site. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Sunderland
The North East has many terraced streets and post-war semis, where rear extensions and loft conversions are popular ways to gain space.
Sunderland sits in Tyne and Wear, about 10 miles south-east of Newcastle upon Tyne. We cover the whole of Sunderland, including postcodes SR1 and SR9.
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 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 Sunderland
Can an annexe be rented out?
Not without further planning permission, as that would make it a separate dwelling.
Can it be accessible?
Yes. Level access, wider doors and a wet room can be designed in.
How long does a garden annexe take in Sunderland?
Typically 10 to 16 weeks on site. Design and approvals beforehand usually take 3 to 4 months.
How much does a garden annexe cost in Sunderland?
In Sunderland, a garden annexe typically costs £1,600–£2,500 per m² of floor area, including VAT at 20% (standard rate). A typical 35 m² project comes to roughly £56,000–£87,500. Your fixed price depends on the survey and drawings.
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.