Covering Harrow
Alongside Harrow, we also cover Brent, Wembley (2 miles to the south-east) and Northolt.
Homes in London
London projects often mean working on period terraces with neighbours on both sides, tight access through the house and conservation area controls, so careful planning and party wall work matter as much as the build.
What does a garden annexe involve?
A garden annexe is a separate single-storey building in the grounds of a house with its own bedroom, bathroom and kitchenette, used by family members as part of the main household. Unlike a garden office, an annexe that people sleep in normally needs planning permission and full building regulations approval.
- Foundations and drainage connections
- Kitchenette and shower room
- Heating, hot water and electrics
What is the guide price for a garden annexe in Harrow?
Indicative costs for garden annexes. London and the South East usually sit towards the top of each range.
| Garden annexes | Guide price incl. VAT |
|---|---|
| Standard specification | £2,400 to £2,900 per m² |
| Good specification | £2,900 to £3,400 per m² |
| High specification | £3,400 to £3,900 per m² |
How is a garden annexe approved in Harrow?
English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.
A self-contained annexe used for sleeping and living normally needs planning permission in England.
What can affect a garden annexe?
- The annexe normally has to remain part of the main household, not let as a separate home.
- Drainage may need a pump if the garden falls away from the sewer.
What are the steps?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
Your questions answered
Do I need planning permission for a garden annexe?
Usually yes, because people will sleep in it. Outbuilding permitted development does not cover living accommodation.
How long does an annexe take to build?
About 14 to 24 weeks on site after approvals.
Who deals with the council for a project in Harrow?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Also covering
- Garden annexes in Brent
- Garden annexes in Wembley
- Garden annexes in Northolt
- Garden annexes in Greenford
Learn more about garden annexes, or see every project we cover in Harrow.