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 Newton Aycliffe?
In Newton Aycliffe, 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. We start from a UK-wide guide and adjust it for the North East, where labour and materials are typically about 10% below average. 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 main things that change the cost:
- Drainage connection distance
- Cladding and finishes
- Access for materials
- 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 Newton Aycliffe?
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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
What we take care of:
- Kitchenette and shower room
- Planning drawings and application
- Electrics and heating
- Foundations and drainage connections
- Glazed doors and windows
- 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 Newton Aycliffe
Across the North East, colliery-era terraces and newer estates sit side by side, so the right project depends on the house type.
Projects in Newton Aycliffe (DL5) are surveyed in person before we quote, so the price reflects your actual property.
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
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about garden annexes in Newton Aycliffe
How long does it take?
Typically 10 to 16 weeks on site.
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.
How much does a garden annexe cost in Newton Aycliffe?
In Newton Aycliffe, 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 Newton Aycliffe?
Yes. We build garden annexes across Newton Aycliffe, including postcodes DL5. 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.
