By the Garden Sauna Guide UK Team · Updated May 2026 · Independent, reader-supported

Do You Need Planning Permission for an Outdoor Sauna in the UK?

One of the most common questions people ask when planning to install an outdoor sauna is whether they'll need to apply for planning permission. The answer, for most homeowners, is reassuring: you probably won't.

The UK's permitted development (PD) rules allow you to build a range of garden structures without formal planning permission, and outdoor saunas fall into this category in the vast majority of cases. However, there are specific conditions and limits you need to understand to stay on the right side of the law.

What Is Permitted Development?

Permitted development is a blanket permission granted by planning law that allows homeowners to carry out certain alterations and build certain structures without submitting a formal planning application. This streamlines the process for common projects and prevents the planning system from being overwhelmed with minor applications.

For garden structures, including saunas, these permissions are defined in Schedule 2 of the Town and Country Planning (General Permitted Development) Order 2015. The rules vary slightly depending on which part of the UK you're in—Scotland, Wales, Northern Ireland, and England have slightly different regulations—but the core principles are similar.

When Your Sauna Qualifies as Permitted Development

For an outdoor sauna to qualify for PD in England, it must meet several key criteria:

Size limits: The building (including the sauna) must not exceed 30 square metres in total floor area. Most standalone saunas are well under this threshold—a typical cabin-style sauna is around 4 × 2.4 metres, which is under 10 square metres.

Height restrictions: The sauna cannot exceed four metres in height to the highest point of the roof. Most single-storey wooden cabin saunas sit comfortably within this limit, typically measuring around 2.1 to 2.4 metres.

Boundary distances: The structure must be positioned at least two metres away from any boundary of your property. This is the rule that catches some people out, particularly in smaller gardens. If your boundary is closer than two metres, you'll need to submit a planning application before building.

Forward of the house: The sauna cannot be positioned forward of the main house line (closer to the road). It must be in the back garden or side garden only.

Materials: The structure shouldn't be used for a commercial purpose, and it must be a subsidiary building to your dwelling—so it's for personal use, not running a sauna business from home.

Key Differences for Temporary Structures

If you're installing a temporary structure—such as a canvas cabin or inflatable sauna pod—the rules shift. Many temporary garden buildings fall outside planning control entirely, meaning they can sometimes be positioned closer to boundaries or erected more quickly without the same formality. However, if the structure is in place for more than 28 days without gaps during a 12-month period, it's typically classified as a "building" and the standard PD rules apply.

Permanent wooden cabin saunas, on the other hand, are almost always classified as structures requiring compliance with PD rules from day one of installation.

What Happens If You Don't Qualify?

If your garden doesn't meet the permitted development criteria—perhaps the boundary is too close or you're in a particularly restricted area—you'll need to submit a planning application through your local authority. This process typically takes 8 to 13 weeks and costs between £200 and £500, depending on your council.

Some properties are subject to stricter rules. If you live in a conservation area, national park, or an area of outstanding natural beauty, permitted development rights may be more restricted. Listed buildings have additional constraints. Check with your local planning authority if you're unsure.

How to Check Your Specific Situation

Before ordering your sauna, take these practical steps:

• Measure your garden: Check the distance from your proposed sauna location to all property boundaries. If it's closer than two metres anywhere, you'll need planning permission.
• Check your postcode: Enter your postcode on your local authority's planning portal to see if you're in a conservation area or other restricted zone.
• Contact your council: A simple email or phone call to your local planning department, referencing permitted development rules for garden buildings, usually gets a straightforward answer. Many councils provide guidance documents online.
• Check your property deeds: Some older properties have restrictive covenants that prevent certain structures. These are separate from planning law but equally binding.

Permanent vs. Temporary: A Practical Consideration

Many people opt for permanent wooden cabin saunas precisely because they qualify for permitted development. They're built to last, blend naturally into a garden, and don't require the ongoing setup or takedown that temporary structures demand. High-quality timber cabins with proper insulation and ventilation typically cost between £3,000 and £8,000, but they're an investment that adds genuine value.

Temporary solutions—canvas structures, inflatable pods, or even barrel saunas—may sound cheaper initially, but they offer less flexibility in placement due to less clear PD rules and require more maintenance.

The Bottom Line

For the majority of UK homeowners with a reasonably sized garden, planning permission for an outdoor sauna simply isn't required. The permitted development rules are designed to be straightforward, and they cover standard garden saunas effectively.

The key is measuring your boundaries correctly, checking your local restrictions, and understanding the height and size limits. If you meet those criteria, you can confidently order your sauna and move forward with installation. If you're in any doubt, a quick conversation with your local planning authority costs nothing and prevents costly mistakes further down the line.