Outbuildings
An outbuilding is a separate structure in your garden, such as a garden room, home office, studio or gym, detached from the main house. AVA Home Design designs outbuildings across London and the Home Counties under permitted development where possible, and prepares a lawful development certificate or full planning application where the size, height or use falls outside permitted-development limits.
A garden room adds space without touching the house: an office away from the family, a studio, somewhere to put the weights. Kept within permitted development, it can often go ahead without a full planning application.
We keep the design inside the permitted-development limits where that is possible. Where it needs more height, or a use beyond incidental, we prepare the planning application instead. Either way you know the route before you commit.
Types
- Garden office or studio
- An insulated, year-round room for working from home or a creative studio. The most common request.
- Garden gym
- A dedicated space for equipment, with the floor build-up and power it needs.
- Garden room or annexe
- A larger room for family use. A self-contained annexe with kitchen and bathroom needs planning permission, not permitted development.
- Storage or workshop
- A practical building for storage, a workshop or a hobby space.
Who this is for
- People working from home who need a separate space
- Homeowners wanting a room without extending the house
- Growing families needing flexible extra space
Frequently asked questions
- Can I build a garden room without planning permission?
- Many outbuildings are permitted development if single-storey with a maximum eaves height of 2.5 metres, an overall height of 4 metres for a dual-pitched roof or 3 metres otherwise, and the outbuildings together cover no more than 50% of the land around the original house. Designated land, and uses beyond incidental to the house, can still need permission.
- Can I sleep or run a business in my outbuilding?
- Permitted development covers uses incidental to the house, not self-contained living accommodation or a separate dwelling. A guest annexe with a kitchen and bathroom, or a building used as a separate home, typically needs planning permission. A low-key home office is usually fine; a business with staff or regular visitors may not be.
- How close to the boundary can an outbuilding go?
- An outbuilding within 2 metres of a boundary is limited to 2.5 metres total height under permitted development. Beyond 2 metres you have more height to work with, up to the 3-metre or 4-metre limits depending on the roof. We position the building to make the most of the rules and your garden.
- Does my garden room need building regulations approval?
- Often not, and the thresholds are specific. A detached building with a floor area not exceeding 15 square metres and no sleeping accommodation is exempt. Between 15 and 30 square metres it is still exempt if it is single storey, contains no sleeping accommodation, and is either at least one metre from any boundary or built substantially of non-combustible material. Add a bed and the exemption falls away, which is the trap in most "garden annexe" plans.
- Where can an outbuilding not go?
- Not on land forward of a wall forming the principal elevation of the house, which rules out most front gardens under permitted development. Permitted development also excludes verandas, balconies and raised platforms, and the building must be single storey. On designated land such as a National Park, the Broads, an AONB or a World Heritage Site, a building more than 20 metres from the house is limited to 10 square metres.
- Should I get a lawful development certificate?
- Where a building is permitted development, a lawful development certificate from the council gives you written proof it was lawful, which is useful at resale and for peace of mind. We prepare and submit it. Where the design exceeds permitted-development limits, we submit a full planning application instead.