The David and Lucile Packard Foundation opened its Los Altos, California, headquarters in July 2012 targeting both LEED Platinum status and net zero energy operation. The 49,000-square-foot facility, designed by San Francisco's EHDD architects, has since achieved both, becoming the largest edifice to earn Net Zero Energy Building Certification from the International Living Future Institute (ILFI).
Known for its commitment to environmental conservation, the 50-year-old nonprofit envisioned its new home (originally covered in GreenSource's November 2012 issue) as an attainable model for high-level sustainable commercial development. In its first year, the Packard HQ generated more than enough energy to meet its needs and is on track to do the same in year two.
"The real accomplishment is that we not only achieved net zero but also compiled an unprecedented amount of data," said Brad Jacobsen, senior associate at EHDD. Collecting information from the building's nearly 15,000 monitoring and control points, and keeping the design and commissioning teams involved during the first year to review the data were crucial to troubleshooting problems and tracking performance.
Net zero operation has been attained through a combination of highly efficient systems and intelligent design features. The building's daylight-maximizing layout, consisting of two long wings surrounding an open courtyard, has contributed to a 30 percent reduction in artificial-lighting energy use. Plug loads have also been cut by 30 percent, with help from workspace occupant sensors and top-rated energy-efficient equipment. A super-tight building envelope and chilled-beam heating and cooling system allow for additional energy savings.
Between July 2012 and July 2013, the foundation said it reduced its energy use by approximately 55 percent, compared to the amount used by a typical California office building of similar size. Total energy consumption for that period was 351 MWh, while the building's 292-watt rooftop solar array produced 418 MWh, a net positive result.
Although first-year performance was in line with projections, energy consumption was slightly higher than anticipated—something Jacobsen attributed to HVAC modeling under-projections and unexpected kinks. Failure on two of the building's four heat-pump modules during the first winter was unusual and unpredictable, and had implications for energy use. Packard VP and CFO Craig Neyman also points to maintaining thermal comfort as one of the biggest challenges faced so far, particularly with last year's record-low winter temperatures. "We've been able to overcome this by increasing efficiency through many system changes and tweaks over the past year," he said.
Overall, employees have adjusted well to the new space. A recent Center for the Built Environment survey places general building satisfaction in the 97th percentile. "One of our biggest surprises is how little demand our net zero energy building places on individual staff members," said Neyman. "Aside from general expectations that staff open and close their windows at appropriate times, behavioral expectations are really no different from those of a conventional building."