Ted Hyman, FAIA, LEED AP BD+C
Phiroze Titina, AIA, NCARB, LEED AP BD+C, CDT, ZGF Architects LLP
The 12-story, 443,387 gross square foot South Tower (a former medical center tower) is part of the 2.4 million gross square foot UCLA Center for the Health Sciences, a complex on the UCLA campus. The South Tower, completed over two phases in 1951 and 1965, was a nine-story bed tower above surgery, post op-recovery, and imaging and pathology suites in the basement levels.
After the 1994 Northridge earthquake, damage assessment and engineering studies funded by FEMA determined that the South Tower's structure was weakened. In response, UCLA developed a comprehensive strategy to create a replacement hospital on the campus, and to perform a seismic upgrade and renovation of the tower to house state-of-the-art research wet laboratories in support of the School of Medicine's research and educational programs. The renovation will bring the tower into compliance with high-rise building codes, improve the thermal performance of the exterior skin, and upgrade core and life safety infrastructure. The tower will be the first research building on the campus to adopt a developer approach under which users implement interior tenant improvement projects as they are identified.
The open laboratory spaces are programmed to be generic and highly flexible environments that can function as wet bench, laboratory support, or dry laboratory space with quick and minimal build-outs. This approach allows the University to develop the building without the need to identify specific user groups and research programs that the building will accommodate. The revamped South Tower will be a key component in the restructuring of School of Medicine research programs along thematic lines rather than by department.
Trying to fit a conventional centralized HVAC design into the tower with its low floor-to-floor height (13 feet 6 inches) would require the exhaust shafts to be relocated on the exterior. It would also create a high initial cost for air handlers and ducts to service the entire tower. Instead, the design calls for each wing to be supplied by a small air handler with a centralized exhaust. The centralized exhaust system will be installed up front, while the air supply system will be installed as users and programs move into the tower. This approach will allow the University to postpone the cost of fitting out the laboratory wings until a specific user or program has been identified for it. The HVAC system is designed to meet minimum ventilation requirements for six air changes per hour, with chilled beams to deal with equipment heat loads.
The design significantly improves the thermal performance of the existing masonry walls, with long stretches of single glazed ribbon windows, by adding R-15 batt insulation behind the masonry walls and replacing the windows with high-performance spectrally selective double-glazed units. These upgrades reduce energy use intensity by 30 percent.
The existing sunshades cover more than two-thirds of the ribbon windows and block daylight penetration into the space as well as views of the outside. These are replaced by a horizontal clerestory sunshade that blocks enough direct sunlight and glare to make the perimeter comfortable for occupants while allowing substantial daylight penetration.
Seven existing exterior stairs serve as means of egress for the South Tower and adjacent connecting buildings. These stairs are being enclosed and pressurized to comply with code requirements for high-rise buildings. New curtain wall enclosures for the stairs are designed to be passively ventilated during normal operation of the building. In case of an emergency that requires evacuation of occupants, the louvers facilitating passive ventilation are automatically closed and the pressurization system turns on. This strategy will create significant energy savings through not having to condition and pressurize the eight- to 12-story stairs year-round.
In conclusion, the seemingly disadvantageous physical characteristics of the former hospital tower such as narrow floor-plates, low floor heights, continuous strip windows, and a structural grid designed to accommodate patient rooms have been turned into advantages in designing an efficient, high-performance, sustainable research building. The design has saved $78 million by retrofitting the existing structure and shell, and energy use has been reduced by 30 percent through right-sizing HVAC equipment, use of chilled beams, daylighting controls, and exterior skin upgrades.