Kilroy Realty Corp. is seeking to create San Francisco’s first office building capable of operating on a net-zero-energy basis, hiring respected architect William McDonough to work the magic.
The proposed six-story building at 333 Brannan St. with more than 175,000 square feet, including 3,000 square feet of ground-floor retail, may also have Kilroy’s first green roof—one with sufficient coverage to help divert 25 percent of the building’s storm-water runoff.
Kilroy’s desire to lead the market in sustainability, the city’s temperate climate and strong municipal support are pushing the real estate investment trust to explore the challenge despite its technical difficulties, executives said.
“We don’t yet fully know the typical tenant’s expectations for net-zero-ready space. We are out trying to understand and prepare for those expectations right now—as is much of the industry ,”said Chris Heimburger, Kilroy vice president of development. “We are trying to better understand the demand for high-performance buildings and how to accommodate a better-educated and more environmentally-conscious tenant.”
If the Leadership in Energy and Environmental Design program and the U.S. Green Building Council capture the sustainability movement’s influence on the built environment over the last two decades, the quest for net-zero buildings looks to be the mantra for the two decades to come.
According to the Vancouver, Wash., -based New Buildings Institute, a 16-year-old nonprofit research and advocacy organization to improve energy efficiency in commercial buildings, a net-zero building is one that creates as much renewable energy on-site as is consumed. But, complicating an already complicated subject, industry has yet to accept a universal definition.
Some argue that building users should be able to buy electricity from independent renewable-energy producers and still claim their buildings and operations as net-zero. Kilroy’s definition of net-zero is a building that has the ability to offset all of its energy usage with renewables, be they onsite or offsite.
Buildings located in tight urban settings often lack the roof surface to accommodate all of the needed solar panels, even if energy consumption is reduced radically, said Stacey Hobart, New Buildings Institute’s communications director. Some believe the buildings also should produce no carbon emissions.
Cupertino’s Apple Inc. said in April that it intends to have net-zero energy operations at its new 3.4 million-square-foot campus. It is an astounding promise, given that the New Buildings Institute says the largest net-zero building operating today is the Putney Field house, a 16,800-square-foot recreation facility in Putney, Vt. The consumer electronics hardware and software maker told the state that it expects to build 650,000 square feet of solar panels on its 176-acre site. Yet even with such an array, the company—while still describing the operation as net-zero—said it expects at times to buy renewable energy from the grid.
“The discussion almost gets theological or rabbinical,” said Edward Dean, an architect who has helped to design a 10,000-square-foot Berkeley branch library to net-zero-energy and carbon standards. “Even the solar photovoltaic panels have a lot of embedded energy in them, so they have to produce energy over several years before it makes up for the energy it costs to produce them.”
The library, now under construction, relies on passive ventilation to keep the interior cool. Rather than a “big fan driving the air through the building,” it is equipped with “tiny fans” that operate as “back-up … if the wind isn’t blowing from the right direction or something,” he said.