Passive Natural Ventilation is used to cool down the fabric of the building, which minimises the required running time of traditional mechanical HVAC systems, in turn reducing the buildings running costs. This can be achieved by the use of roof ventilators normally used in factory or warehouse facilities along with a source of inlet or make up air such as louvres installed at low level. Another form of natural ventilation is facade or window automation. This is created by automating windows or louvres within the facade creating healthier internal environments. These systems can be manually operated via a simple day to day switch, alternatively they can be fully automated using temperature, wind, rain and even Co2 sensors, all used to monitor the internal/external environment and determine if the windows should be open or closed. These systems can also be controlled by Building Management Systems (BMS). Similar systems to the facade automation system previously described can be installed in domestic dwellings. These systems consisting of electric awning window chain winders also known as window actuators, this type of actuator can also be used on skylights alternatively linear actuators can be used depending on the application. Home automation can be operated by a simple switch or intelligent controls can offer a fully automated system using sensors, 24/7 timers, etc. These systems can also be controlled by third party Home Automation Systems the work via WIFI like Zigbee and Z-wave or wired systems such as Cbus.