01
Outbuilding or annexe
Garden rooms used for hobbies or work can often fall under permitted development, with height limits near the boundary. Once it has its own kitchen and bathroom for living, planning permission is usually required.
Garden annexe 30 m²
Design a 30 m² garden annexe or garden room
Plan a guest annexe, home office or studio of around 30 m² in your garden, with exact measurements and drawings to discuss with your council.
Design my garden annexe
02
Smart use of 30 m²
Fit a kitchenette, shower room and sleeping area in centimetres, try a mezzanine under a pitched roof and furnish with real dimensions.
03
Plot and boundaries
Enter your plot size and see footprint, coverage and distances to boundaries directly in the sketch.
04
Drawings to share
With Project Pass you get a site plan, floor plan, elevations with ground line and a section with ridge height on A3.
THE RULES AT A GLANCE
Size, height and distance to the boundary
Typical permitted development limits for outbuildings in England – check your council for annexes.
Footprint
Outbuildings may cover no more than half the garden area around the original house.
Height
Max 2.5 m if within 2 m of a boundary; otherwise 4 m with a dual-pitched roof or 3 m for other roofs.
Use
Hobby, studio or office use is incidental. Sleeping and living with kitchen and bathroom usually needs planning permission.
Location
Not forward of the principal elevation. Extra limits apply in conservation areas and for listed buildings.
THREE WAYS TO USE 30 m²
Layouts that fit
Starting points you can redraw in centimetres and furnish with real dimensions.
Granny annexe
Kitchen, accessible shower room and a mezzanine above, keeping the ground floor open for living.
Guest room and office
Kitchenette, shower room and a flexible space – office by day, guest room by night.
Studio or pool house
Open space, large glazing to the garden, storage wall and WC.
FROM SKETCH TO SITE
How it works
- 1
Sketch and place
Enter your plot, try volume and roof shape and see boundary distances.
- 2
Plan in centimetres
Fit kitchen, bathroom and sleeping area with real furniture.
- 3
Produce drawings
Site plan, floor plan, elevations and section to scale on A3.
- 4
Check with the council
Confirm permitted development or apply for planning permission and building control.
THE DRAWING SET
What councils usually ask for
Four drawings straight from your model – with the same dimensions everywhere.
Site plan
Position on the plot with distances to boundaries.
Floor plan
Rooms, fixed fittings, doors and windows.
Elevations
All four sides with ground line and materials.
Section
Ceiling height, ridge height and roof pitch.
Illustrations are simplified examples. Rules differ across England, Scotland, Wales and Northern Ireland.