Starting layout: Manufacturer-led. This is an illustrative design prompt; check furniture, equipment and internal clearances.
Start with the layout
Choose a purpose-designed sauna system and follow its requirements for heater clearances, lining, insulation and ventilation.
Get the specification right
Have the electrical installation or flue designed and installed by appropriately qualified people. An ordinary garden office specification is not a sauna specification.
Plan the details early
Plan safe access, changing space and drainage, and confirm planning and building-control requirements for the complete proposal.
Build a complete brief
Record internal dimensions, intended use, ventilation, services and access. Share the same brief with every supplier so quotes can be compared. Check planning and building-control requirements before committing to a particular height or footprint.