G. David Schoenhard, AIA, LEED AP, with Maki San Miquel Paulson, LEED AP, Wulff Architects
Colorcon's new Global Headquarters, global data center, and research and development laboratories are in a Leadership in Energy and Environmental Design (LEED®) Gold-certified, 90,000-square-foot complex on a 26-acre site one hour northwest of Philadelphia. Energy challenges included the heat of data center equipment and fresh air required for laboratories, but efficient fixtures, distribution, and controls have assured thermal comfort and reduced energy costs. The site is bordered by residential neighbors who are welcome to use a community path through the site, re-created as wildflower meadows and reforested habitat. An extensively planted roof garden and lunch terrace is watered by stormwater runoff. Only 22 percent of the building's façade is fenestrated, but over 80 percent of occupants have access to daylight and views. Occupancy sensors determine ventilation and lighting.
The most important decision from a financial and environmental viewpoint was to "right-size" the building and parking capacity of 169 surface spaces. The design team preserved 50 percent of the approximately 26-acre site for flora and fauna, including a continuous ecosystem of native field plants. Site ecosystems include field, meadow, forest, and wetland, and all are designed to encourage native fauna, while discouraging invasive fauna, such as Canada geese.
The berm provides multiple benefits and was created by utilizing soil from the data center's sunken floor excavation. The massing next to the data center acts as a heat sink to conserve energy and shield the sound of the emergency generator. The height of the berm decreases the apparent bulk of the building in the eyes of neighbors and minimizes the parking lots.
Bike and hiking trails meander through a forested buffer zone at the property edge, while bike racks are conveniently located near the building. These community paths encourage healthy exercise for neighbors and employees and provide opportunities for informal communication. The buffers recreate native flora, encourage native fauna, and filter and absorb storm water, thus decreasing the size and first cost of detention basins. Over the entire site, 3.5 million gallons of irrigation water are saved annually.
Bi-level site lighting tied into the central lighting control system is used, which turns off or dims non-security lights when no longer needed. Full cut-off, energy-efficient fixtures minimize light pollution, which aids migrating birds, nocturnal fauna, and the adjacent neighborhood.
The roof garden is irrigated by rainwater collected from the roof and stored under the parking area within the berm. Absorbing sound and vibration, the vegetation provides a different habitat for fauna who favor dry conditions, and the thermal mass of the planting media aids in energy conservation. Next to the employee entrance is a vertical green wall, which moderates heat exchange into the building.
Natural light is capitalized on while the thermal efficiency of the building envelope decreases energy demand. Mechanically, the load is reduced by measuring demand and leveraging outside air, while efficient equipment decreases greenhouse gas emissions. Daylight harvesting and energy-efficient light fixtures, distribution, and controls decrease electricity usage. As a result, 29 percent of energy costs are saved while delivering the highest standard of thermal comfort.
Daylight design and thermal efficiency shape the two-story, steel-frame, slab-on-grade construction. Sawtooth roofs admit light at the clerestory level, while overhangs minimize glare. At the same time, the glazing is optimized to constitute only 22 percent of the façade, which decreases solar heat gain and increases thermal efficiency. The majority of the over-hung, high-performance glazing faces either east or south, allowing maximum sunlight. Glare-control window shades are timed according to sun position, and daylight-harvesting controls dim the overhead fluorescent lights. Bio-based insulation, made of American soy products instead of petroleum, was chosen for thermal efficiency. Roofing with a high Solar Reflectance Index limits heat transfer into the building.
There are three areas of occupancy: laboratory at 26,500 net square feet (NSF), office at 46,000 NSF, and data center at 6,100 NSF. The data center and laboratory areas use a central chiller for cooling, and the office areas use air-cooled package roof-top units. A central hot water boiler system provides heat for the total building. Demand ventilation saves substantial amounts of energy by using the occupancy sensors to determine ventilation. In the laboratories, run-around coils recover heat from the exhaust air during the winter. In the data center and laboratories, free-cooling condensers in chillers allow cooling with outside air when conditions warrant, resulting in free-cooling and partial free-cooling. Also in the data center, hot aisle/cold aisle equipment cabinet arrangement achieves more efficient heat transfer. Water savings of 48 percent over conventional construction are achieved by using low-flow shower, faucet, and toilet fixtures, including dual-flush automatic valves and waterless urinals.
A rigorous Construction Air Quality and comprehensive commissioning program was developed, and a full flush-out was performed on the entire facility prior to occupancy. A full 95 percent of construction waste was diverted from the landfill through sorting, recycling, and re-purposing materials. Two years of excellent construction management produced a clean, green building with minimum waste in the process.
Occupancy has the most environmental impact. A sophisticated Measurement and Verification Plan tracks energy consumption by function, allowing for continuous performance improvement in the energy systems of the building. Environmentally preferable maintenance reduces indoor air pollution while improving the quality of the wastewater. Occupants use central recycling areas in each copy/coffee area. Drivers of low-emissions, fuel-efficient vehicles are rewarded with preferential parking spaces. Only one smoking area is allowed on the grounds. An alliance of corporate policies, design decisions, and occupant education has encouraged active engagement of occupants in environmental stewardship, which is the greatest benefit of all.
G. David Schoenhard, vice president of Wulff Architects, Inc., has over 25 years experience in the design of office and laboratory facilities. A frequent presenter at professional conferences and symposia, Mr. Schoenhard is committed to the design of efficient and healthy buildings through the innovative use of materials, technology, and design techniques. As a LEED Accredited Professional, he brings his extensive experience and knowledge of sustainability issues to major projects in the Mid-Atlantic region. Wulff Architects, founded in Philadelphia in 1992, provides architecture, interior design, and planning services to corporate, institutional, governmental, and industrial clients.