Buildings today are automated because the systems are complicated so we depend on the Building Controls System (BCS) to operate the equipment. We also depend on a Computerized Maintenance Management System (CMMS) to keep a record of what was repaired and to schedule required maintenance.

SCADA, BCS and CMMS can all be hacked. Maintenance staff may think the BCS is not connected to the Internet, but as a Registered Architect I have yet to see a building that is not connected to the Internet. If your building is connected to the Internet, I assure you that your BCS has already been hacked...