Choose the sauna type: traditional wood-fired, electric, or infrared
Select a suitable location with proper ventilation, drainage, and structural support
Check local building codes, permits, and electrical requirements
Decide the sauna size and layout
Gather materials: framing lumber, insulation, vapor barrier, interior wood, fasteners, door, heater, benches, lighting, and ventilation parts
Build or prepare the foundation or floor base
Frame the walls and ceiling
Install insulation in walls, ceiling, and floor as needed
Add a vapor barrier on the warm side of the insulation
Install interior wall and ceiling paneling with sauna-safe wood
Build and install benches at comfortable heights
Install the sauna heater according to manufacturer instructions
Add heat shields and safety clearances around the heater
Install proper ventilation openings for air intake and exhaust
Fit a sauna-rated door with a safe opening mechanism
Install sauna-safe lighting and electrical components
Seal joints and trim with sauna-safe materials
Test the heater, ventilation, and temperature control
Inspect all safety clearances, wiring, and structural connections
Clean the sauna and run it through a test heat cycle before use