or a wing, can be shut down for routine maintenance, for renovation, or in an emergency. Seemingly minor incidents in a laboratory building can have significant financial consequences for want of a readily accessible service shutoff. For example, if a water pipe breaks and water runs for several hours, it may cascade through several floors of a building, damaging ceilings, flooring, wall finishes, and scientific equipment. Water damage, electrical fires, and flammable gas leaks can easily be prevented with strategically placed shutoff valves. The services to each laboratory and to each wing or floor should be isolated and easily shut off. Small laboratory installations, maintenance, or minor repairs become major incidents when the entire building must be shut down to change one washer in a valve that would not close. Shutoffs on deionized water systems are commonly overlooked.
Utility Distribution. Utility chases and interstitial spaces are used to distribute utility services throughout a building. Since laboratory buildings are much more utility intensive than are office buildings, routing the utilities throughout the building is more difficult.
Use of interstitial spaces can simplify utility distribution in a laboratory building and can provide greater flexibility over the building's lifetime. Housing utility services and equipment between occupied floors permits routine maintenance and modification with minimal disruption of the activities of laboratory users. Designing a laboratory building with interstitial space may significantly increase the construction cost, but that cost likely will be recovered over the lifetime of the building through decreased maintenance costs, decreased cost of modification and renovation, and decreased disruption of the primary activities for which the laboratory building was built.3
Utility chases for ventilation ducts, plumbing, and electrical services can run vertically or horizontally, in a wall or along the ceiling. When distributed at the ceiling, ducts and pipes can be left exposed as an intended design element or concealed with a drop ceiling. Servicing or modifying utilities distributed at the ceiling will frequently disrupt the activities of the laboratory staff and other building users.
Box 3.13 lists a variety of locations for placement of utility chases. A utility service corridor, which is very much like an interstitial space except that it can be horizontal or vertical, is a passage within the building with utilities running along its walls either vertically or horizontally. A horizontal utility service corridor is for use by building maintenance personnel and is not intended as a circulation corridor for other building users. DiBerardinis et al. (1993) includes an