The skeletal structure of the building was that of a two storied, standard steel beam system with open web steel joists, erected on reinforced concrete foundation walls and footings. The building envelope consisted of brick veneer with the interior consisting of metal studded partitions with drywall. All concrete floors were concrete slab, either on fill or suspended on metal decking. The building was constructed on a sloped site with the second level serving as the front of the building and providing a ground level main entrance. This level had two identical wings that flanked the main entrance of the building, each with 12500 square feet (1157 m2) of floor space. In addition to hallways and restrooms, each wing contained patient waiting and exam rooms, faculty and medical resident offices, as well as nursing and administration areas. Since the building had two wings with identical layouts, each being used for identical outpatient care, it provided a unique opportunity to conduct a controlled study. The lower level housed the labs and support services with exit at the rear of the building. The HVAC system consisted of four main areas. The lower level was served by two separate but equally sized AHUs, each rated at 10,000 CFM. The upper level was served by two equally sized but separate units, each rated at 14,000 CFM. All units were balanced, and had separate outside air intake zones. The building was completed in December 1997 and opened on schedule in January 1998. All antimicrobial treatment of the test wing was completed before the building was opened for occupancy.