Why Do Sauna Doors Open Outwards?

If you've ever looked closely at a traditional sauna, you may have noticed one small but deliberate design feature: the door almost always opens outwards.

At first glance, it seems like a minor detail. In reality, it's a carefully considered design choice that improves safety, maximises usable space, supports the flow of people through the sauna and aligns with decades of Nordic design principles.

Whether you're buying a home sauna or specifying one for a hotel, spa or wellness club, here's why outward-opening doors have become the industry standard.

Safety Is the Number One Reason

The primary reason sauna doors open outwards is safety.

Saunas operate at temperatures of between 70°C and 100°C, and while they're perfectly safe when used correctly, prolonged heat exposure can occasionally leave people feeling light-headed or dehydrated.

If someone feels faint or loses their balance while trying to leave the sauna, an outward-opening door is far less likely to become obstructed. A person collapsing against an inward-opening door could potentially make it more difficult to open from the outside, whereas an outward-opening door can usually still be pushed open quickly to assist them.

For this reason, most reputable sauna manufacturers design their cabins with outward-opening doors and easy-to-operate catches that allow rapid exit if needed.

Most Sauna Doors Don't Lock

Another feature many first-time buyers notice is that traditional sauna doors rarely have locks.

Instead, they are usually fitted with magnetic catches, roller catches or simple wooden closures that keep the door shut without locking it.

This is entirely intentional.

A sauna should never become a confined space. Anyone inside should always be able to leave quickly and easily without searching for a key or operating a complex locking mechanism.

It's one of the simplest but most important safety features built into modern sauna design.

It Maximises Space Inside the Sauna

Saunas are designed to make efficient use of every square metre.

If the door opened inwards, it would require a clear swing area inside the cabin, reducing the available space for benches and restricting where people could sit or move.

By opening outwards, the entire internal footprint remains usable.

This is particularly important in compact two- and four-person saunas, where even a small amount of extra floor space improves comfort and usability.

For commercial saunas, it also allows designers to maximise seating capacity without compromising access.

It Improves the Flow of People

Commercial saunas often welcome dozens—or even hundreds—of guests every day.

An outward-opening door creates a more natural flow for people entering and leaving the sauna, particularly during busy sessions at hotels, spas and contrast therapy venues.

Guests can exit quickly without stepping backwards or manoeuvring around an inward-swinging door, helping maintain a smoother circulation of people through the space.

It's Consistent with Commercial Best Practice

While building regulations vary depending on the country and application, commercial sauna manufacturers and designers generally favour outward-opening doors because they support safe evacuation and straightforward access.

Many public saunas, hotels and wellness facilities also combine outward-opening doors with:

• non-locking door systems
• tempered safety glass
• easy-to-grip timber handles
• lightweight magnetic catches

Together, these features create an environment that's simple to use while prioritising guest safety.

Does an Outward-Opening Door Help Retain Heat?

Only slightly.

Some people believe outward-opening doors are designed to keep more heat inside the sauna.

In reality, the difference is relatively small.

The primary factors affecting heat retention are the quality of the insulation, door seals, glazing and how frequently the door is opened.

However, an outward-opening door does avoid swinging through the hottest part of the room, creating slightly less disturbance to the heated air as people enter and leave.

While this isn't the main reason for the design, it's a small practical benefit.

Why Are Most Sauna Doors Made from Glass?

Modern saunas commonly feature tempered safety glass rather than solid timber doors.

There are several reasons for this.

Glass allows natural light to enter the sauna, creating a brighter and more spacious feel. It also enables people outside to see whether the sauna is occupied and provides reassurance in commercial settings where staff may need to monitor guest wellbeing.

The glass used is specially tempered to withstand repeated heating and cooling cycles and is considerably stronger than standard household glass.

Can a Sauna Door Open Inwards?

Technically, yes.

Some bespoke or older sauna designs use inward-opening doors, particularly where room layouts make this unavoidable.

However, most reputable manufacturers recommend outward-opening doors because they provide better safety, maximise usable space and align with established sauna design principles.

If you're designing a new sauna, an outward-opening door is generally the preferred option.

Can You Reverse a Sauna Door?

It depends on the manufacturer.

Some modular sauna systems allow the door orientation to be changed during installation, while others are designed to open in only one direction.

If door positioning is important—for example, due to the layout of your garden or wellness room—it's always worth confirming the opening direction before ordering.

The Verdict

An outward-opening sauna door may seem like a small design detail, but it's the result of decades of practical engineering and user experience.

It improves safety, makes better use of the available space, supports smoother movement in busy commercial settings and reflects the design principles followed by many of Europe's leading sauna manufacturers.

Combined with a non-locking catch, tempered safety glass and thoughtful layout, it's another example of how the best sauna designs prioritise both performance and user wellbeing.

So, the next time you step into a sauna, take a look at the door. It isn't just opening the right way by chance—it's opening that way by design.

Frequently Asked Questions

Why don't sauna doors have locks?

Traditional sauna doors are designed to open easily from both sides. Instead of locks, most use magnetic or roller catches so users can leave quickly if they feel uncomfortable or unwell.

Do commercial saunas always have outward-opening doors?

Most do, as outward-opening doors are widely regarded as the safest and most practical option for high-traffic environments. Individual designs may vary depending on the manufacturer and local building requirements.

Does an outward-opening sauna door keep more heat inside?

Only marginally. Heat retention depends far more on insulation, glazing, door seals and construction quality than on the direction the door opens.

Why are sauna doors made from glass?

Tempered safety glass improves visibility, allows more natural light into the sauna and creates a brighter, more open feel while remaining strong enough to withstand repeated heating and cooling cycles.