Finnish Sauna: Design

Designing your sauna

The design of a sauna is of course related to your needs: how many bathers you want to accommodate, what kind of heater you are using and the limitations placed by the existing building. Even a small sauna should be large enough to fit at least two bathers. Designs vary from a modest sauna in an apartment to a large sauna in a separate building on the lakeside.

You must have at least one shower. Really old saunas do not have running water, but people carried water in by the bucketful. In any case you need some water for cleaning up. A second shower will be useful if many people are bathing at the same time.

In an apartment

The sauna should ideally be placed next to an exterior wall, so that you can arrange fresh air ventilation through the wall. If your sauna is not near an exterior wall, arranging proper ventilation will be slightly more difficult.

If you can arrange it, the sauna should be situated so that there is a suitable changing room nearby. Your guests in particular will appreciate a quiet place to change. Placing the sauna near a balcony or patio -- if you have one -- will allow you to use it for cooling down after a bath.

A sauna cabin

When you go to the trouble of building a separate sauna cabin, you want to have place for at least four people in the sauna, possibly more. The shower room only needs room for two at the same time since there is usually no rush when bathing and one can wait a while before showering.

In addition to the sauna and shower, there should be a dry room to undress and change. Ideally this would be an additional room between the shower and the other parts of the house, but can also be a screened section of the cabin's main room or the porch.

Sizes and measurements

The size of your sauna will depend on several factors: the number of bathers, the placement of the benches, the space requirement of the heater and the method of heating.

The sauna should be 2000 to 2200 mm (6-7 ft) high, so that there will be 1000-1200 mm (3 1/2 - 4 ft) above the highest bench. The height of the bench was traditionally such that the bathers' feet would be above the heater during bathing. This is no longer a strict requirement if the sauna is properly heated so that the entire room is sufficiently hot.

You should have at least 600 mm (24 in) of bench space per bather. You can get by with less, but try to make the sauna wide enough to lie down on the bench. The bench should be 450-900 mm (17-35 in) deep for pleasant sitting. Again, this allows you to lie down without falling. The lower benches used as steps to the highest bench should be 300-400 mm (11-15 in) deep.

The benches and the heater

The benches can be placed in many different ways in the sauna. The simplest and most space efficient is a long bench on one side of the room. Other possible designs are the L-shape and the U-shape where the benches are on two or three walls of the sauna with the heater in the middle.

(Click to enlarge.)

What wood to use for the benches? Here is what the Finnish Building Information Centre (Rakennustietosäätiö) recommends the following:

	Benches	Bathroom furniture
Spruce (scandinavian)	OK	OK
Pine	Possible	OK
Larch (Lehtikuusi)	Possible	No
Aspen (Haapa)	OK	No
Alder (Leppä)	OK	Possible
Birch (Koivu)	No	Possible
Abachi	OK	Possible
Teak	Possible	OK

The heater should be placed a safe distance away from the door and benches. If your heater is right next to the door of the sauna, the door should be hinged on the heater's side. This will help you avoid burns, since the door will open so that you see the heater when you enter the room. The door should open out of the sauna. There should be a 50 mm (2 in) gap between the door and the floor. This is an important part of a sauna's ventilation system. Remember that the handle of the door must be wooden: any other material will be untouchable when heated.

Details

There should be sufficient storage space in the dressing room to keep a few clean towels at hand. In the shower room, wooden stools are the best choice for seating. Wood is a great material even in the dressing room, it's pleasant to the touch and surprisingly easy to keep clean if you don't abuse it.

You will get all the details and specifications you need from these guides published by the Rakennustieto. They are all in Finnish but check the links on the upper right hand of the page: there are plenty of pictures of different designs with measurements.
Sauna design
Sauna structures
Benches and furniture