When it may be permitted development
These are the common features that keep a project on the simpler route.
Does a garden room need planning permission in England? As an outbuilding it is often permitted development, but height, use and sleeping accommodation change the answer. Check the national rules and your exact property first.
A garden room is treated as an outbuilding under England's national permitted development rights, so a home office or studio at the bottom of the garden often qualifies. The two things that most often tip it into needing permission are height — especially near a boundary — and using it as living or sleeping accommodation.
These are the common features that keep a project on the simpler route.
These are the usual triggers that push a scheme beyond straightforward PD rights.
The tool is designed to answer the first question most homeowners have: is this worth pursuing, and what is most likely to block it?
CanUBuild checks your exact address against national datasets for conservation areas, listed status, Article 4 directions, flood risk and tree preservation orders.
The workflow captures the deciding details: height, distance to the boundary, footprint relative to the garden, and intended use.
You see decided applications nearby so you can judge how your local planning authority has treated similar garden rooms.
Often not. As an outbuilding, a garden room used incidentally can fall within national permitted development — but height near a boundary, footprint, designations, or any residential use can require a full planning application.
National permitted development sets maximum heights for outbuildings, and the limit is lower within two metres of a boundary. Many garden-edge rooms are caught by this, so position and height need checking together.
Using a garden room for sleeping or as self-contained accommodation makes it no longer incidental to the house, which takes it outside permitted development and generally requires planning permission.
Confirm the height against the boundary distance, whether your permitted development rights are intact, and whether any conservation or Article 4 designation applies. An address-level check answers these first.
Search for the address, choose your project type, and get a planning feasibility answer based on permitted development rules, constraints, and local precedent data.