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 Blyth?
In Blyth, 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. Prices across the North East are typically 10% below the UK average for this kind of work, which is reflected in the range for Blyth. 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 |
What moves the price most:
- Cladding and finishes
- Access for materials
- Heating type
- Kitchen and bathroom
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 Blyth?
Before anything is built in Blyth, we confirm which approvals apply 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
On a typical garden annexe we handle:
- Building control sign-off
- Electrics and heating
- Glazed doors and windows
- Planning drawings and application
- Foundations and drainage connections
- Kitchenette and shower room
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 Blyth
The North East has many terraced streets and post-war semis, where rear extensions and loft conversions are popular ways to gain space.
From NE24 outwards, we take on projects throughout Blyth and the surrounding parts of Northumberland.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about garden annexes in Blyth
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 much does a garden annexe cost in Blyth?
In Blyth, 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.
Do you build garden annexes in Blyth?
Yes. We build garden annexes across Blyth, including postcodes NE24. Every project starts with a free home visit.
Does it need building regulations?
Yes, as it contains sleeping accommodation and services.