Automation in residential and business buildings, hotels, hospitals, shopping malls, museums, etc., developed out of the efforts to save energy. (About 45% of the total energy produced is spent in buildings). Till today, the list of reasons for installing automation in buildings has grown significantly longer:

Let several examples testify to the advantages of automated buildings over classical ones:

• The heating turns off automatically when windows are opened.
• If the quantity of light entering through the windows increases, the artificial lighting in the building will automatically reduce or turn off.
• Windows receiving sunlight are automatically protected by blinds or awning, thus reducing the inflow of heat and decreasing the demand for air-conditioning.
• The night heating program is defined separately from the daylight one, so the temperature is reduced in rooms not used during the night.
• The movement sensor alerts the computer that a room is empty; after a while, the computer will turn off the lights and turn down the heating.
• The status of the building can be checked or changed remotely, using web or WAP interfaces. Some devices in the building can be turned on or off by sending an SMS or an e-mail, etc.

One or more networked process computers control vital functions in an automated building, with supervision and control done from the Building Control Centre. Various functions are brought together to form subsystems:

• Heating, ventilation, and air-conditioning
• Lighting and blinds control
• Intrusion detection
• Fire safety
• Video surveillance
• Time attendance and access control
• Guard control and visitor management
• Multimedia devices and household appliances