A corner sauna is a cabin with a diagonal front that tucks into the angle of a room, and it exists because that corner is the space most houses are not using. It is one of the few sauna shapes designed around a house rather than around a sauna, and it involves a specific trade you should understand before buying.
Why the shape works in a house
A rectangle in the middle of a basement or a spare bedroom eats circulation space on every side. A corner unit uses two walls you already own, needs clearance on only the diagonal face, and leaves the room usable. In a finished basement, a garage bay or a large bathroom it is frequently the only shape that goes in without a renovation.
What the diagonal costs you
Benches follow the walls, so you get two shortish runs meeting at the corner rather than one long bench. That seats people comfortably and makes lying down awkward unless the cabin is large. If stretching out matters to you, measure the longest straight bench a corner unit actually gives you rather than trusting the stated seat count.
Where the heater goes
Usually on one of the two wall faces, or in the corner itself on a floor standing model, with the guard rail eating a slice of the floor. That is the same clearance any cabin needs but it is more noticeable in a small triangular plan, so check the floor plan drawing rather than the exterior dimensions before deciding two people will fit.
Measuring for one
Corner cabins are quoted as two wall lengths and a diagonal, and the diagonal is what has to come through your door. Measure the wall runs, then the door opening and any stair turn on the way in. Check the corner is actually square, because an out of square corner leaves a gap that is visible and awkward to trim.
Questions people ask about corner sauna
Is a corner sauna smaller than a rectangular one?
In floor area usually yes for the same seat count, but it uses space a rectangle wastes, so in a real room it often fits where a larger cabin cannot.
Can you lie down in one?
Only in a large one. The diagonal turns one long bench into two shorter runs, so check the longest straight bench rather than the seat count.
What should I measure?
The two wall runs, the diagonal face, and every doorway and stair turn on the route in. The diagonal is what has to fit through the door.