By DENIS HAYES March 5, 2014
When the Bullitt Foundation determined to create the greenest commercial building in the world, we embarked on a quest that was mind-numbingly complex but enormously rewarding. I’d assumed that the toughest challenge would be to build a zero net energy six-story building in cloud-covered Seattle. That was difficult, but far from the hardest of the goals we set out to meet.
Our goal for the Bullitt Center was ridiculously ambitious. In a flight of rhetoric, I told the architects that I wanted them to do for buildings what the 707 did for commercial aircraft, what the first Macintosh did for personal computers, what the Prius did for automobiles. I wanted the Bullitt Center to redefine the whole category.
The instrument we chose toward that end was the Living Building Challenge. Like the X Prize (but, alas, without the monetary award), the LBC lays out a set of “stretch goals” that are so difficult that many people believed them to be impossible in a building of commercial scale located downtown in a major city. The requirements (which fill a small book) include:
A Living Building must generate as much energy on-site each year as it uses. Other than low-grade heat, all its energy is electricity. Nothing can be burned in a Living Building.
A Living Building must use only the rain it can collect on its roof to meet all its water needs, including potable drinking water. Treated gray water must be returned to the hydrological cycle right on site.
A Living Building must be constructed without using 362 common building materials that are toxic, carcinogenic, mutagenic, endocrine disrupting, or otherwise harmful to humans and other forms of life. The building contains more than 1,000 components that had to be screened.
All wood in a Living Building must either be recycled or come from forests certified to meet the very high standards of the Forest Stewardship Council.
A Living Building must use only composting toilets. We could not find any other examples of composting toilets in six-story buildings.
Figuring that this would probably be the only large building I would ever have the chance to develop, I decided to push the envelope even further than the LBC required:
The Bullitt Center does not look at all like an organism, but it functions like one. It has a brain and nervous system that determine whether the windows should be open or closed, whether the external shutters should be raised or lowered, whether lights should be on or off. Occupants can override these systems, but only for a half hour at a time. The Center is a strong-willed building that, like a life form, always seeks homeostasis.
I set a design life of 250 years. The planned obsolescence built into large modern buildings is obscene, a triumph of net present value methodology over common sense.
The Bullitt Center can be easily accessed by bases, trolley, and light rail; it has ample parking for bicycles (and two showers on every floor). However, the Center has no parking lot for automobiles.
The upper floors of the Center are serviced by an efficient, regenerative elevator. It is fully ADA compliant, with easy access to people with disabilities and those carrying heavy loads. However, it also has a glass-enclosed “irresistible stairway” with great views of the Olympic Mountains. The stairway lures most people to climb.
To the greatest extent possible, the Center is daylit. We Homo sapiens have spent 99 percent of our existence on this planet responding to circadian rhythms and to full spectrum sunshine. We are happiest, healthiest, and most productive in natural daylight. Most of the Center’s artificial lighting is full spectrum LEDs. Still, I didn’t need to turn on a lamp (except in the men’s room) between April and the end of September.
We chose the members of the senior team—Miller Hull, PAE, Point 32, Schuchart Construction, and Solar Design Associates—for their demonstrated talent and creativity, but also for their ability to play well with others. We employed an integrated design process, with diverse charettes before beginning the design process. Professor Rob Pena from the University of Washington’s Integrated Design Lab attended weekly meetings of the entire team for more than two years.
Net Positive Energy
We determined the maximum surface area that could be covered with solar panels, the maximum efficiency then available in commercial panels, and the average insolation per year. We persuaded the city to create an ordinance providing for “solar canopies,” allowing arrays to extend over public sidewalks. Solar Design Associates calculated that, in an average year, our 570 SunPower E19 245-watt modules yield a maximum capacity of 242kWp to generate about 257,000 kWh annually. We built in a buffer of 27,000 kWh and set 230,000 kWh as the energy budget for the building. In architectural terms, for a building with about 50,000 square feet, that translates to an energy use intensity (EUI, expressed asKBtu/ft2) of 16.
Putting that in context, the average existing commercial building in Seattle has an EUI in the low 90s. A new building built to code would be in the low 50s. A LEED Platinum building with all its energy credits would be in the low 30s. So an EUI of 16 was a challenge. It was not as hard as I expected.
PAE of Portland, our principal engineering firm, decided to expand into Seattle, and wanted to locate in Bullitt Center. After carefully measuring the energy consumption per employee in Portland, they found they’d have to reduce electricity use by about 70 percent. They selected computers, monitors, printers, copier and task lightsfor the Seattle office to use as little energy as possible. The new standard computer setup, with a thin client server and two monitors/desk uses, only 17 percent as much energy as the system it replaces—with no loss of computing power or functionality.
The Center is still undergoing commissioning. The third floor is heated and lit, but it has not yet been leased and occupied. Some tenants are still building their staffs and moving toward full occupancy. And the first three tenants arrived only about Earth Day (April 22), 2013. Therefore our dataset is limited. Even so, it offers some insights.
The solar equipment, installed under the deeply experienced guidance of Steven Strong, performs as expected. When the sun shines, it generates power. For the eight months through December 31, it produced almost exactly as much power as predicted.
The surprises were on the demand side. During those eight months, the Center used only about half as much energy as expected, for an astonishing EUI of 8.4! During these eight months a six story building in cloudy Seattle produced more than twice as much power from sunshine as the building used.
But this must be taken with a grain of salt. It includes spring, summer, and autumn when Seattle’s sunshine is most abundant, but not winter, and the Center was not fully occupied. After another year of operation, we will have a much clearer sense of how the completed and fully-tenanted building operates. But at this point, it appears likely to prove a stunning success.
Denis Hayes, president and CEO of the Bullitt Foundation, was national coordinator of the first Earth Day in 1970 . He served as director of the National Renewable Energy Laboratory during the Carter Administration, and as chair of the Board of Trustees for ASES.
This article appears in the March-April 2014 print edition of SOLAR TODAY. Subscribe today!