Modern facilities have become very different from what they once were. Emerging technologies and concerns about safety, accessability, and environmental issues are now significant factors in determining the character and infrastructure of buildings for undergraduate programs in math and science. Buildings must now accomodate sophisticated communications networks, in addition to services for air-conditioning, power distribution, and water piping systems. They must be safe for students, faculty, and the environment. Finally, they must have an infrastructure that is efficient in terms of initial and long-term cost and fexible enough to accomodate changes in program use in the years ahead. Planners should aim for a building in which the individual systems work together to provide an environment for students and faculty that is functional, cost-effective, comfortable, engaging-and safe.