Double skin facades have become a major architectural element in office buildings over the last 15years. A double skin facade can provide a thermal buffer zone, solar preheating of ventilation air,energy savings, sound protection, wind and pollutant protection with open windows and nocturnalcooling. Commercial buildings with integrated double skin facade can be very energy efficientbuildings with all the good qualities listed above.However not all double skin facades built in the last years perform well.