For the most part, the only  real difference is location.
Outdoor saunas may be built in your own outdoor structure like a cabana, garden shed or bunky.  If that is the plan, you can install one of our material kits inside your structure. The sauna kit is basically the inside "skin" of the sauna.
There are also many styles of pre-fab outdoor saunas; including cabin style, barrels, pods and others.