Courthouse meets desert challenge

THE FEDERAL GOVERNMENT knew the desert environment of Tucson, Ariz., offered challenges to buildings but also saw a benefit, and used it to its advantage in building the Evo A. Deconcini US. Courthouse.

The $67.4 million, 413,000-squarefoot Deconcini takes its design cues from the desert. The hot climate helped craft the exterior look with elements such as loggias, overhangs, alcoves and deeply set windows, says Bill Murray, project manager for Hardy Holzman Pfeiffer architects.

Taking advantage of dry conditions for most of the year, Dean Helma, director of engineering on the project with Leo Daly Co., says the government was able to downsize the courthouse's chiller plant by reducing its load by 200 tons through evaporative cooling.

Low E glass, which has a U value of .29 and a shading coefficient of .44, was used on three facades, while the west facing glass used "fritted" or etched glazing with an even lower shading coefficient of .30. The shading coefficient is the measure of solar heat gain through the window. Clear glass has a rating of 1.0. The cost of the glazing was offset by an energy savings performance contract on the HVAC system offered by Johnson Controls, Helma says. E-mail comments to angela.maas@tradepress.com.