Clearing the LEED Hurdle
Two of the renovation's most important goals were to make the building more energy efficient and to achieve LEED certification. Complete replacement of the HVAC system was the key to meeting both objectives. At the same time, says Chilton, this change presented one of the greatest challenges. "Even though the mechanical systems needed to be larger than the existing systems," he explains, "they had to have a minimal impact on the historic aesthetic of the building."
The existing heating and cooling system—a four-pipe system with fan-coil units placed around the perimeter on all floors—was fully removed. In its place, a new high-efficiency heat pump system was installed. The ceiling-mounted heat pump units are hidden above the ceiling tiles on the third and fourth floors but are clearly visible—a definite compromise—in the first- and second-floor offices, where the large air handlers and ducts have been painted to match the ceiling color.
In surpassing the 26-point minimum for LEED certification (this project earned 29 points), the city benefited from the building's location in a dense, inner-ring suburb with available bus transportation and limited parking capacity. Placing water-conserving fixtures in the restrooms earned additional points for water use reduction. The nature of the project also limited the amount of demolition that was required, so City Hall scored high on building reuse credits. The use of low-VOC adhesives, paints, and carpets was a no-brainer. And two additional points were earned through the city's purchase of renewable energy certificates that encourage green power.
Project: Renovation and Restoration of University City Hall, University City, Mo.
Architect: Trivers Associates, St. Louis—Andy Trivers (historical architect); Andrew Smith (project manager); Bill Chilton (project architect); Lawson Harris (project designer)
M/E/P, Fire Protection, and Structural Engineer and LEED Consultant William Tao & Associates—Bruce Levitt (principal-in-charge and LEED consultant); Sara Seagrist (mechanical engineer); Jim Kuba (electrical engineer); Greg Roth (plumbing engineer); Mark de la Fuente (lighting designer); Allan Seidel (fire protection engineer); Bill Manz, Mark Schell (structural engineers); Christine Ward (LEED administrator); Jerome Logan (commissioning agent)
Size: 33,495 square feet
Historical Wood Windows Manufacturing, historicalwoodwindows.com
Inefficient windows were partly to blame for the old building's poor thermal performance, and many of them leaked, as well. All the windows were removed and delivered by truck to Historical Wood Windows Manufacturing, a Kansas City, Mo., company that restored the sashes and installed new insulated glass. Entirely new reproduction windows were built for the second floor, whose original windows had been replaced earlier with ones that didn't match.
Superior Waterproofing & Restoration Co., superiorwaterproofing.com
What began as a small-scale job evolved into a comprehensive cleaning and repointing of the brick and limestone façades. In this process, the building is cleaned with a chemical mixture and high-pressure water. Then, all the mortar joints are ground out with diamond blades to a half-inch depth and replaced the old-fashioned way. Minor reglazing of failed terra cotta was also part of the job.
Sloan Valve Co., sloanvalve.com
The combination of the LEED imperative and the desire to demonstrate water conservation as a public education tool led to the specification of dual-flush flushometers in the restrooms. The mode for liquid waste saves ½ gallon of water—about 30 percent—for each flush. In addition, the men's rooms are equipped with waterless urinals.