Remember that walls and particularly the ceiling of an electrically heated sauna room requires efficient thermal insulation. Once square metre of stone, glass or similar non-insulated surface increases the heater power requirement as much as if the sauna room cubage was increased by 1,2 m3. If the internal sauna room wall consists of non insulated log, the corresponding factor is 1,5. Also, pay close attention to sauna room ventilation. An efficient air circulation ensures that the bathers can enjoy a clean indoor air that is easy to breathe.