There have been significant advances in the design and engineering of intelligent buildings that not only accommodate major advances in office technology but provide better physical and environmental settings for the occupants. These architectural and engineering advances, demonstrated in various parts of the world, can be summarized into four major system categories: enclosure innovations; heating, ventilation, and air conditioning system innovations; data/voice/power connectivity innovations; and interior system innovations. Results of studies of over 20 intelligent office buildings, conducted by a multidisciplinary expert team of the Advanced Building System Integration Consortium based at Carnegie Mellon University, are presented.