The Space
The room is the foundation of every decision that follows. Its dimensions set the bench layout, the heater size, the electrical spec, and the ventilation positions. Get this information locked down before anything else is ordered or built.
My room
My sauna is 92″ wide × 66″ deep with a vaulted ceiling averaging 78″. I label the walls A (back), B (right, heater wall), C (front), and D (left). This wall-labeling convention carried through the entire design process and into the contractor drawings — it prevented a lot of confusion.
The room was converted from a storage area, so the dimensions were fixed before the sauna design began. This is the most common situation for home sauna conversions and it shapes every decision that follows.
Key space decisions
- Door placement: Must swing outward — a safety requirement. A person who loses consciousness cannot be trapped inside. Plan the door position before framing begins.
- Heater wall: Lock this in before any other layout decisions. Everything — bench layout, ventilation, electrical rough-in — is planned around the heater position.
- Ceiling height: Aim for
84″minimum at the highest point. At78″average with a 36-inch upper bench, I have 42 inches of clearance above the seat — workable, but worth checking at your specific ceiling geometry before fixing bench heights. - Adjacent spaces: Note what's on the other side of each wall before specifying insulation. Exterior walls need more depth; walls shared with living spaces need careful vapor barrier detailing.
Minimum practical dimensions
| Use | Minimum | Comfortable |
|---|---|---|
| One person | 4′ × 4′ | 5′ × 6′ |
| Two people | 5′ × 6′ | 6′ × 8′ |
| Lying down (one person) | 4′ × 6′ | 5′ × 7′ |
Floor and drainage
Concrete or tile floor, sloped ¼″ per foot toward a drain. This is far easier to plan during construction than to add afterward. Use removable cedar duckboards for bare-foot comfort — they lift out for cleaning and allow drainage beneath. No carpet, vinyl, or laminate; all degrade at sauna temperatures.
My contractor built the room 2 inches shorter than specified. The walls were up before I caught it, which meant redesigning the bench layout. After any framing or construction work, take your own measurements of the finished room before designing benches or ordering materials.