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 Maesteg?
In Maesteg, a garden annexe typically costs £1,650–£2,600 per m² of floor area, including VAT at 20% (standard rate). For a typical 35 m² project that is roughly £58,000–£91,000. Building costs in Wales run about 8% below the UK average, and the figures for Maesteg are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (24 m²) | £39,500–£62,500 |
| Typical project (35 m²) | £58,000–£91,000 |
| Larger project (49 m²) | £81,000–£127,500 |
| Rate per m² | £1,650–£2,600 |
The biggest cost drivers are:
- Drainage connection distance
- Kitchen and bathroom
- Cladding and finishes
- Size and layout
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 Maesteg?
Before anything is built in Maesteg, we confirm which approvals apply in Wales. In Wales an annexe with sleeping accommodation usually needs planning permission; outbuildings under permitted development must be incidental to the house.
Building regulations in Wales are set by the Welsh Government. Approval comes from the council’s building control service or a registered building control approver, with inspections during the work and a completion certificate 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
What we take care of:
- Kitchenette and shower room
- Planning drawings and application
- Electrics and heating
- External cladding or brickwork
- Insulated walls and roof
- Foundations and drainage connections
How long does it take?
The build itself usually takes 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 Maesteg
Wales has many terraced valley streets, stone cottages and post-war estates, so extension designs are shaped by slopes, materials and local character.
From CF34 outwards, we take on projects throughout Maesteg and the surrounding parts of Mid Glamorgan.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 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 Maesteg
Do I need planning permission for a garden annexe in Maesteg?
In Wales an annexe with sleeping accommodation usually needs planning permission; outbuildings under permitted development must be incidental to the house.
How long does it take?
Typically 10 to 16 weeks on site.
Can an annexe be rented out?
Not without further planning permission, as that would make it a separate dwelling.
Who approves a garden annexe in Maesteg?
Planning matters in Maesteg go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much does a garden annexe cost in Maesteg?
In Maesteg, a garden annexe typically costs £1,650–£2,600 per m² of floor area, including VAT at 20% (standard rate). A typical 35 m² project comes to roughly £58,000–£91,000. Your fixed price depends on the survey and drawings.
Does it need building regulations?
Yes, as it contains sleeping accommodation and services.