A sauna can turn a good sweat into a great party, and you'll find outdoor models that can fit eight, 10 or even 12 people comfortably. Unfortunately, the party sauna may not fit in that unused corner of your yard
You may be tempted to go as big as you can afford, but a sauna that monopolizes your entire outdoor space will seriously limit your options for future additions, may turn off prospective home buyers if you eventually want to sell, and will probably look pretty odd.
A good approach is to go with the largest sauna you can afford among the models that will fit easily in the available space. Even a small yard can accommodate a multi-person sauna -- a 5x7-foot structure can fit three or four bathers comfortably. You'll just need to pare down the guest list.
Next tip: Be honest -- are you really the party type?