Building automation system (BAS) jobs focus on the installation, design, and repair of equipment and controls regulating the basic systems of a given facility. More specifically, BAS is a centralized system that controls the heating, air conditioning, ventilation, and lighting inside of an industrial, commercial, or residential building. Some systems also control security and other features. As a BAS technician, your duties include installation of system components, such as sensors and appliances, repair and maintenance, and regular system-wide safety and functionality tests. BAS specialists and engineers design systems, determine overall effectiveness, and choose components that meet the building’s energy and operations needs. Some engineers also program or customize embedded software that controls the BAS.