Case Studies: Cambria Office Facility

L. Robert Kimbal & Associates

Buildings and occupants rely ever more on mechanical services. Traditionally, a building's basic structure accounted for about 80 percent of its costs. With the transition to skeleton frame structures over the last hundred years - as opposed to load-bearing masonry - that cost has fallen to some 20 percent. On the other hand, the cost of building services has ballooned, with mechanical systems typically consuming 35 percent of the building budget. Today, more is spent on services than on any other building component.

We place tremendous importance on environmental comfort, leading to these profound changes within building expenditures. But these broad distinctions between costs for a building's basic structure and mechanical services do not sufficiently address the interplay between building components. Structure, which encompasses envelope, impacts services. For instance, consider Pennsylvania's Cambria Office Facility in Ebensburg, where investment in a high-performance, triple-glazed window system eliminates the need for perimeter heating - reducing mechanical system first costs, to say nothing of operational energy.

The Cambria project also illustrates designers using triple glazing in concert with traditional daylighting strategies, to achieve energy consumption goals. The project is oriented longitudinally along an east-west axis, to maximize south and north exposures. Light shelves on the south-facing windows provide shade and reflect light inside, with an ultra-reflective ceiling driving daylight into the building. Roof overhangs shade second-floor south-facing windows to reduce cooling loads. Clerestory windows over the center of the second floor provide daylight from two directions, which increases daylight and distributes it more evenly to reduce glare.