John F. Kennedy School of Government, Harvard University, Cambridge MA
Architect: Architectural Resources Cambridge
William
Bobenhausen, then President of Energy Design Collaborative of Scarsdale, New
York served as the energy consultant to the Harvard University Planning Office
for the Belfer Center, a 45,000 square foot addition to the existing 105,000
square foot John F. Kennedy School of Government. Built in 1978 and compliant
with the energy code, the original Kennedy School of Government building
consumed 98,000 BTU/sf/yr. The Belfer Center was designed to require only 45,200
BTU/sf /yr.
Questioning the traditional assumption that additional chiller capacity would be required to meet the new load, William Bobenhausen conducted detailed studies that included a telling analysis of façade shading from piers and setbacks, and self-shading created by the L-shaped building plan. The analysis concluded that the existing chiller capacity in the Kennedy School of Government could service the added space. An initial cost savings of approximately $200,000 resulted - savings that were vital in keeping the project on budget and on schedule.
Analysis led the design team to reduce the size of the glass area in the Belfer addition, and to situate the windows to avoid solar heat gain yet admit visually useful daylight. Automatic dimmer controls with fiber-optic sensors were specified for inclusion in the new addition and the Kennedy School of Government. When daylight is available, these devices automatically reduce perimeter lighting, and so reduce heat output from the lights as well. Such a strategy trims cooling loads and peak demands, while extending lamp and ballast lives.
For improved efficiency, comfort, and acoustics, triple glazed windows were recommended. Wall and roof areas were to have insulation that achieved a heat transmission factor of U=0.05. Such an improved envelope allows professors to work more comfortably in their offices during weekend or nighttime setback periods. With a tighter envelope, building start-up time is also reduced considerably. A rigorous and highly interactive design process led to a solution with unique architectural character - one that is sensitive to user needs yet is quite energy-efficient.
The Belfer Center project led to other Harvard University energy consultations. For the Business School, a study of retrofit window treatment options for the dormitories was completed. To improve comfort in the Business School's Kresge Faculty Dining Hall, plagued with both overheating and tremendous heat loss from large single-glazed window areas, retrofit measures were proposed which would control these conditions.