A garden sauna is one of the best ways to bring the wellness ritual home, but before you choose a spot at the bottom of the garden there is one question worth answering early: do you need planning permission? For most garden saunas in the UK the answer is no, because they fall under permitted development. There are important exceptions, though, and getting this right from the start saves a lot of stress later.
This guide explains the general UK rules in plain English. It is a starting point rather than formal advice, so always confirm your own situation with your local planning authority before you build.
The short answer: usually permitted development
A garden sauna is generally treated like any other garden outbuilding, such as a shed or summerhouse. Outbuildings are normally covered by permitted development rights, which means you can build them without a full planning application, provided they stay within a set of limits. If your sauna meets those conditions, you are free to go ahead.
The main conditions to stay within
Permitted development for outbuildings comes with rules on size, height, and position. The key ones to keep in mind are:
- The building must be single storey.
- Maximum eaves height of 2.5 metres, and a maximum overall height of 4 metres for a dual-pitched roof, or 3 metres for any other roof.
- If the sauna is within 2 metres of a boundary, its overall height must not exceed 2.5 metres.
- Outbuildings must not cover more than half the total area of land around the original house.
- The building should be to the rear of the house, not forward of the principal elevation facing a road.
- It must be for a purpose incidental to the enjoyment of the home, which a sauna is.
Most garden saunas are comfortably within these limits, which is why they so rarely need an application.
When you probably do need permission
Permitted development rights are reduced or removed in certain situations. You are more likely to need planning permission if:
- Your home is a listed building, where separate listed building consent may also be required.
- You live in a conservation area, national park, or an Area of Outstanding Natural Beauty, where tighter rules apply, especially to buildings at the side of a property.
- The sauna would sit forward of the front of the house.
- Your permitted development rights have been removed, for example by a planning condition on a newer property. This is worth checking on any recent build.
- You plan to sleep in the building or use it as self-contained living accommodation, which changes how it is treated.
Building regulations are a separate question
Planning permission and building regulations are two different things. Even when a garden sauna does not need planning permission, building regulations can still apply, particularly around electrical work and, for larger buildings, structural and fire safety matters. Any electrical installation in an outbuilding should be carried out by a qualified electrician and certified. A reputable installer will handle this properly as part of the build.
How to check your own situation
The safest approach is simple. Note the size and position you have in mind, then contact your local planning authority or use the government’s Planning Portal to confirm whether your plans fall under permitted development. If there is any doubt, you can apply for a Lawful Development Certificate, which gives you formal confirmation that the sauna is lawful without needing full permission. It is a small step that gives real peace of mind, especially if you sell the house later.
Planning your garden sauna the right way
Siting, size, and design all affect both the rules and the result, so it pays to plan them together. Our complete UK guide to garden saunas walks through the whole process, and if budget is on your mind, our sauna cost guide sets out what to expect. When you work with a bespoke builder, all of this is considered from day one so your sauna fits your garden and the rules alike.
Talk to a bespoke sauna builder
Skotlanti designs and builds bespoke garden and outdoor saunas across the UK, sized and sited to make the most of your space. If you would like help planning a sauna that keeps everything above board, get in touch and we will guide you through it.
