Do i need planning permission to build a garden room with a toilet?
Garden Rooms with Toilets
This is one of the questions we are asked most often. There is a lot of information online, and some of it can be a bit conflicting. Before you look at planning rules, it helps to be clear about what you want from your garden room. With this understanding, you can make an informed decision on whether planning permission is needed.
In this article we look at the topic in more depth and explain when you will and will not require planning permission for a garden room with a toilet.
When You Should Not Need Planning Permission
If your garden room is being used as an office, gym, hobby space, teenagers hangout, or studio, then a toilet is usually allowed without planning permission. This falls under the rules of permitted development, as long as the building itself meets the usual size and placement guidelines.
Adding a toilet can make your space far more practical. Nobody wants to leave a workout to run back to the house or interrupt a long day of work for a bathroom break.
Building Control Rules
When it comes to building control, the rules are slightly different from planning permission. As long as your garden room falls within Permitted Development guidelines and is under 30 square metres in size, you generally do not need formal building control sign-off for the structure itself. However, the inclusion of a toilet changes the picture. While the room may not require inspection, the installation of the toilet, basin, and any associated plumbing or electrics must comply with building regulations. This means that the plumbing should meet building control standards. Drainage, water supply, and electrical work must be carried out to approved specifications, and with regards to the electrics, will need to sign off. In short, the building may be exempt from control, but the facilities inside it are not, so compliance is essential to ensure safety, legality, and peace of mind.
At InFrame Garden Rooms all our garden room plumbing, from a cloakroom to full shower room in an annex is building control compliant, including adding a 24 hour storage, 300L underground pumping station with high level audio and visual alarms.
Definitions
A cloakroom is typically defined as a small room containing a toilet and basin, offering convenient facilities without taking up much space. For added comfort, you can choose to include hot water in the basin by installing an electric heater within the vanity unit. In contrast, a shower room goes a step further, incorporating a toilet, basin, and shower to provide a more complete bathroom setup within your garden room.
When Planning Permission Is Required
If the intention is for someone to live permanently in the garden room, then it becomes a separate residential unit. At that point the council will class it as a self contained living space, which requires planning permission. This applies whether the person is a relative, a lodger, Airbnb or anyone staying long term.
A toilet alone does not make a garden room a dwelling, but a toilet combined with other features such as a full kitchen and sleeping area usually will. If you are unsure, it is always worth checking before you invest in the fit out.
planning permission rules
When you WILL need planning for your garden room
Height:
Single Pitch Roof is over 2.5m
Dual-pitched roof ≤ 4m
Placement: The placement of the garden room is infront of the frint elevation of the house
Coverage: The garden room occupies more than 50% of your outdoor space.
Use: If it is intended as a guest annex with a toilet/shower, councils may see it as a separate dwelling.
What Is Involved In Installing A Toilet
Once you have decided to add a toilet to the garden room the practical requirements need careful design and execution.
Groundworks are one of the most significant elements of the installation, as they determine how waste and water will be managed. We need to consider suitable drainage routes, pipe runs, a reliable water feed, and adequate ventilation to ensure the system functions safely and efficiently. In many cases, this means trenching through the garden to connect the toilet to the main soil stack of the house. Where a direct connection is not possible, alternative solutions such as a macerator or a pumping station can be used to move waste to the nearest suitable outlet. Each option comes with its own costs, technical requirements, and maintenance considerations, so it’s important to weigh them up before committing. Proper design at this stage not only avoids costly mistakes but also ensures your garden room remains compliant with building regulations and provides long-term convenience.
These details are all reviewed and can be quoted for during a site survey by a qualified project manager.
Our Expert Advice
A toilet can make your garden room more useful and more comfortable for day to day life. As long as the space is not being used as a permanent home, you should not usually need planning permission. The main work sits within the ground preparation and drainage design, so choosing a company that has experience in this area will make the process much smoother.
If you would like to explore adding a toilet to your garden room, we are always happy to talk through what is possible for your space.
Planning Permission & Building Control for Garden Rooms with Toilets
| Situation | Planning Permission Needed? | Building Control Needed? | Notes |
|---|---|---|---|
| Garden room under 30 sqm, with Permitted Development rights in tact without a toilet. To be used as office, gym or extra space. | ❌ Not usually | ❌ Not usually | Falls within Permitted Development |
| Garden room under 30 sqm, with Permitted Development rights in tact with a toilet. To be used as office, gym, occasional sleep over room or extra space. | ❌ Not usually | ❌ Not usually | Ancillary use allowed, but plumbing/heating must meet building regs. |
| Garden room under 30 sqm, built under Permitted Development rights with a toilet. To be used as permanent living accommodation | ✅ Yes | ✅ Yes | Treated as self‑contained accommodation, requiring both planning and building control. |
| A garden room over 30sqm, with or without a toilet | ❌ Not always, site dependant | ✅ Yes | Generally falls outside Permitted Development due to ground heights around the building and must meet full building regs. |
| Garden room where Permitted Development Rights are NOT in tact, eg, a flat or over 50% of the garden etc | ✅ Yes | ❌ Not always but over 30sqm then Yes | Not allowed under PD; all facilities must meet regs. |
