Because of their energy-intensive nature, laboratories make excellent candidates for sustainable design. While at the beginning of the green building movement some believed energy-efficient, environmentally sustainable, high-performance laboratories to be unrealistic or unaffordable, advancements in expertise and technology, coupled with lower materials costs, have changed that perception.
CDC strikes Gold
The Centers for Disease Control and Prevention (CDC) Building 110 (Figure 1), just outside Atlanta, GA, is the first major high-performance federal laboratory to receive LEED Gold certification, demonstrating that environmental sustainability, superior operational performance, and a "great place to work" are not mutually exclusive, even on a public-sector budget.
Figure 1 CDC Building 110.
The building's concept is one of maximum flexibility and adaptability to accommodate rapid program shifts. With seven high-throughput laboratories collectively capable of performing over 100,000 tests daily, this complex, multidisciplinary building's requirements for environmental control, security, and safety create unique circumstances that the building must respond to as research agendas evolve.
The building is home to the National Center for Environmental Health, and much of the work performed there falls into the biomonitoring arena, the direct measurement of toxins in people. As such, one of the facility's most important environmental requirements is the elimination of trace metals and chemical contamination (e.g., outgassing) from controllable sources such as construction materials, finishes, furnishings, and landscaping. The client's environmental goals are further supported by the CDC's commitment to leadership in sustainable design and their understanding that a sustainable workplace would increase employee satisfaction, aid in recruiting the "brightest and best" and reduce energy consumption. LEED certification was required from the outset, although LEED Gold was not.
Planning for sustainability
Figure 2 - Diagram showing floors and interstitial levels.
The designers realized from the outset that the challenge was not only to capitalize on sustainability opportunities, but to deliver multiple benefits using sustainable design techniques. From preliminary design through occupancy, sustainability was viewed from a global project perspective to maximize return on every dollar invested.
An example of this approach was the inclusion of interstitial levels between floors (Figure 2). This provided equipment and storage areas outside of laboratories while also creating 16-ft maximum laboratory ceiling heights, enhancing occupants' spatial perception and allowing significantly larger windowed areas for increased daylighting. Thus, the addition of interstitial floors produced numerous integrated benefits, from reducing energy consumption and increasing employee satisfaction to increasing laboratory flexibility. Further, because the interstitial floors precluded the need for an additional laboratory floor, no cost penalty was incurred (Table 1).
Table 1 - Savings realized with interstitial floors
Daylighting
Figure 3 - Laboratory ceilings reaching 16 ft.
The building design underwent extensive modeling and analysis to maximize human-environment connections through effective daylighting and views. Though building orientation was fixed before design commenced, each facade was configured to maximize daylighting, optimize sizes and angles of exterior shading devices, and minimize glare.
The laboratories' 16-ft maximum-sloped ceilings allow large amounts of daylight to penetrate up to 30 ft into the building (Figure 3). Because walls separating laboratory zones—and those separating laboratories from the public corridor—have clerestory windows, 70% of the total building area is daylit, with over 90% of occupants able to enjoy visual connections to the outdoors.
This exceptional building transparency makes daylight the primary illumination source during daytime, supplemented as necessary by ambient indirect and localized task lighting. Daylight sensors work in conjunction with dimmable fluorescent fixtures to provide consistent illumination regardless of weather or time of day; occupancy sensors turn off fixtures when spaces are vacant.
This integrated approach to illumination reduced lighting power needs by 25.3% while helping to make Building 110 an unusually appealing, visually comfortable workplace.
HVAC, energy, and indoor air quality
Laboratories typically consume 5–10 times the energy of commercial office buildings, largely due to ventilation requirements. Building 110's design minimizes ventilation loads by separating office and laboratory blocks with individual ventilation systems for each, making it possible for the office block to utilize an airside economizer while also meeting the laboratories' 100% once-through air requirement. The result is an impressive 23.7% building energy efficiency despite 100% outside air requirements in the laboratories and challenging climatic conditions. Reducing air changes by 40% during unoccupied hours has also proven effective in reducing energy consumption. Further, since interstitial spaces are not ventilated at the same rate as laboratories, operating costs are lower than with "ventilated storage" located inside the laboratories.
The efficiency of this design has enabled a 25.7% reduction in fan power, 16.7% reduction in cooling, and 32.3% reduction in heating—remarkable savings for this type of laboratory. A humidification system allows for increased occupant comfort and lower temperatures in winter, producing additional energy savings.
Deck-to-deck partitions, segregated chemical storage areas, walk-off mats, and elimination of landscape-based chemical pollutants contribute to the facility's high indoor air quality levels. A construction Indoor Air Quality (IAQ) management plan and extensive building flush-out ensured high indoor air quality levels throughout construction. Low-emitting materials were used in construction and fit-up, with specifications requiring products free of added urea formaldehyde and stipulating Carpet and Rug Institute "Green Label Certified" carpets and padding. Even the ceremonial entry is faced with zinc due to its benign environmental characteristics.
Laboratory reconfiguration
Due to national security concerns, the designers were charged with maximizing building flexibility in case of the need to shift research focus overnight. To meet this goal while reducing costs, waste, and health risks, a variety of structural, mechanical, and interior designs were employed to provide a holistic approach to flexibility.
Equipment and casework were designed for easy reconfiguration; the only fixed components are fumehoods, ducted biosafty cainets, and sinks. Remaining casework comprises mobile tables and base cabinets that can be rapidly reconfigured into numerous layouts. Wet columns with vertical risers allow for horizontal runs to be easily installed at any time (Figure 4). Swing interstitial space can be utilized as needed without demolition or construction, vastly reducing the amount of renovation waste and significantly lowering costs.
Water cycle
Figure 4 - Flexible utility drop.
The entry-area landscape design is parklike in appearance, adding to the building's aesthetic appeal. Landscaping is comprised exclusively of native and adapted plantings requiring no potable irrigation water, pesticides, or herbicides, adding to the project's ecological integrity and keeping laboratories free of landscape-based pollutants.
Rainwater is collected from the roof in cistern-like containers lining the front of the building, with each container connected to a series of artistically shaped rills (Figure 5) through which the water flows into raingardens. These drainage rills constitute a subject of interest and discussion: a working symbol of CDC's dedication to sustainability. Through the use of raingardens and restored landscaping, 100% of stormwater is retained on-campus, even during severe storms, eliminating the need for municipal stormwater system connections.
Figure 5 - Rainwater cisterns and rills.
Condensate from HVAC chillers is collected for irrigation. Because the facility is located in a hot, humid climate, 10.4 gpm of condensate is generated, with 100% of condensate captured and stored in an underground water vault. The stored condensate provides 100% of site irrigation needs, eliminating any requirement for potable irrigation water. This strategy yields the highest flows of condensate during the summer months, effectively meeting peak irrigation demands.
Materials and construction
To mitigate negative environmental impact, 46% of construction materials were sourced regionally and 21% include recycled content, with over 56% of construction waste diverted from landfills through a variety of processes and uses. Highly textured and patterned carpet tiles hide wear and reduce installation waste, with terrazzo flooring used in certain nonlaboratory areas for its superior life-cycle performance. Static-free laboratory flooring was selected based on research requirements and life-cycle costs.
Conclusion
Building 110 has emerged as part of a growing industry standard for excellence, successfully combining sustainable design with laboratory functionality and comfortable, appealing workspaces. Its success is best expressed by the client's presentation to the design team of the "CDC Partners in Public Health Award" for "excellence in an innovative approach to Building 110, resulting in a world-class, flexible, energy-efficient, and employee-friendly laboratory facility." It is the first time such an award has been presented to a team outside CDC research.
With sustainable products and techniques becoming more effective and affordable all the time, opportunities for laboratory sustainability are continually increasing. With environmental concern, energy costs, and competition for top researchers continually increasing, deciding whether or not to pursue sustainable design may well determine whether a laboratory remains a viable research space, or soon becomes a dinosaur, in the years ahead.
Mr. Mlade is Research Manager, Science & Technology Sustainability, and Mr. Watch is Principal, Science & Technology, Perkins+Will, 1382 Peachtree St. NE, Atlanta, GA 30309, U.S.A.; tel.: 404-443-7540; fax: 404-892-5823; e-mail: [email protected].