Covering Beckenham
Beckenham sits 8 miles south-east of London, with Catford 3 miles to the north and Croydon 4 miles to the south-west.
Homes in London
Terraced houses dominate many London neighbourhoods, so most projects involve shared walls, narrow access and a party wall process. Conservation areas are widespread, and some boroughs have their own mansard and basement guidance.
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
- Accessible design options for older relatives
What will a garden annexe cost?
Typical ranges for garden annexes. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.
| 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 |
Do you need permission for a garden annexe in Beckenham?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
A self-contained annexe used for sleeping and living normally needs planning permission in England. Permitted development for outbuildings does not cover living accommodation.
What should I think about before starting?
- A level threshold and wider doors make the annexe suitable for later life.
- Council tax treatment depends on who lives there; check with your council.
How does the project run?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- We visit and measure. A surveyor checks the house, the boundaries and the ground, and discusses what is realistic.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
What people ask before starting
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.
How do I get a price for garden annexes in Beckenham?
Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.
Garden annexes in nearby towns
- Garden annexes in Catford
- Garden annexes in Croydon
- Garden annexes in Blackheath
- Garden annexes in South Croydon
Learn more about garden annexes, or see every project we cover in Beckenham.

