Outdoor saunas are the most common way to own one in the United States, because putting the heat, the humidity and the eventual smell of hot cedar outside the house removes most of the problems an indoor installation creates. The trade is that everything the building would have provided, you now provide: a level base, a power supply that survives the weather, and a shell built to stand in rain and snow.
Barrel, cabin and pod
A barrel sauna is a horizontal cylinder of staves, which heats efficiently because there is less air above your head to warm and sheds water naturally off its curve. A cabin is a conventional rectangular room with a pitched or flat roof, easier to fit with a full-height door and benches at two levels, and usually the roomier choice for the same footprint. A pod is a rounded or teardrop shell, the most expensive shape per person and the one bought for how it looks in a garden. The price gap between styles is generally wider than the gap between brands within a style.
The base and the delivery
An outdoor sauna needs a level, drained base that will not settle: gravel or pavers is the usual answer, a poured slab the expensive one, and a lawn is not a base. It arrives as heavy freight, often on a pallet that a truck leaves at the kerb, so there has to be a route from there to where it will stand and usually several people to move it. Buyers underestimate this step more often than any other, and it is the one that cannot be fixed after the crate is delivered.
Power, wood and weather
An electric heater above roughly six kilowatts generally needs a dedicated higher-voltage circuit run out to the sauna, which is an electrician's job and frequently the second largest line in the whole project. A wood-burning stove avoids that and adds a flue, clearances and a fuel habit instead. Whichever you choose, check what the maker says about winter use and about treating the exterior, because an outdoor cabin is a timber building and it needs the maintenance any timber building outdoors needs.
Questions people ask about outdoor saunas
Which outdoor sauna style is most efficient?
A barrel, generally, because its curved shape leaves less air above head height to heat. The practical difference is smaller than the marketing suggests once cabins are properly insulated.
Do outdoor saunas need a concrete slab?
Not usually. They need a level, drained base that will not settle, and gravel or pavers meets that for most models. A slab is an option rather than a requirement.
Can an outdoor sauna be used in winter?
Yes, and many owners prefer it then. A traditional heater reaches high temperatures regardless of the outside air; an infrared cabin loses more of its heat to the cold, which is worth weighing if winter is the main season.