Environmental conditioning or HVAC contributes to many aspects of a 'satisfactory worker environment'. One of the most significant aspects of a 'satisfactory worker environment' is getting the Building Automation System (BAS) to correctly manage the system operations. In some ways, the BAS represents the brain and nervous system for the building body. And thus, careful attention is required when attempting rehabilitation or performing 'brain surgery'. When reviewing BAS systems in existing large buildings, it is important to evaluate the entire operation similar to the way a good doctor's plan includes a patient stress screening. Various operations can be tested in the Commissioning processes, including reviewing a listing of Hot-Cold calls and conducting a 'laptop' survey at the sensors to reveal details of system performance similar to an EEG. This Paper will present details of the rehabilitation of a BAS system at a pharmaceutical company's National Training Center campus. Built in New Jersey in the early 90s, the campus is comprised of three, five-story buildings, with approximately 240,000 total square feet (22300 SM). Each building includes a low temperature air supply system with Series Fan Powered VAV units. Following three years of effort in the continuously occupied buildings, the project is now complete and already shows much improved living conditions for the Owner. The information of this paper is intended to convey the aspects of a detailed replacement of BAS using descriptions similar to those used by a Medical Professional to treat a patient. The Owner expressed a desire in and found greater value in the improved reliability of system operations even more than generating minor energy savings. While the improvement in maintenance staff's ability to maintain occupant's comfort could not easily be calculated, the Owner believed it represented a major financial benefit.