It may be a first: an office building with a net electricity use of zero or less, that burns no fossil fuels for heating and produces no greenhouse gas, and that makes the people working there at least as comfortable as those in conventionally heated and cooled buildings. The building, in San Jose, Calif., opens in October, and if all goes according to plan, it will raise the bar for designers of energy-efficient buildings worldwide. Though other so-called z-squared buildings exist, they are highway rest stops, nature centers, and event locations, not office structures with computers and printers and cubicles full of employees.
”We’ve hoisted the flag and said we’re the first,” says David Kaneda. ”No one yet has stepped forward to question that.” He owns the San Jose building, and his Santa Clara, Calif.based firm, Integrated Design Associates (IDeAs), did the electrical and lighting design and will occupy the ground floor.
David Kaneda shows off the solar panels and skylights of his new building.
The building was once a windowless bank, designed in the 1960s when banks were meant to be riot-proof concrete bunkers. Today, with the remodeling nearly completed, it is modern art: the exterior is broken up with rows of windows and swaths of blue and gray paint, while solar panels adorn the roof, with skylights pushing up in between.
Kaneda embarked on the project of renovating the old bank in September 2005, with the goal of creating an environmentally friendly building that could earn a Platinum rating—the highest—from the U.S. Green Building Council, an association of builders in Washington, D.C. At that time, global climate change was not in the forefront of public consciousness, and the council’s standards were not much in the public eye. So Kaneda thought he was being very forward-thinking when he proposed to renovate the bank to meet the council’s specifications for building materials, water use, indoor air quality, and—most important—energy use.
But when Kaneda hired architect Scott Shell, from EHDD Architecture, in San Francisco, to work on the project, Shell went even further, suggesting they design a building with no net electricity usage and no carbon dioxide emissions.
”It was a shock to me when he said that,” Kaneda recalls. He didn’t know of any commercial buildings that had gone that far.
The idea appealed to Kaneda, and the two decided they would disconnect the natural gas pipes running to the building and find heating alternatives. They would stay on the electric grid but install enough photoelectric panels to cover the entire energy load—about 30 kilowatts, generating more electricity than the building uses during the day but pulling a small amount off the grid at night. Since they’d be limited by the size of the roof, they’d have to be clever about energy use.
”To cut down on energy use, you’ve got three areas to address,” Kaneda says, ”lighting, heating and cooling, and plug load—that is, the computers, printers, microwave ovens, and other things you plug into the wall.”
To reduce the amount of energy used for lighting, Kaneda’s builders sawed through the concrete perimeter of the building to install windows and skylights. Special window glass lets visible light through but blocks infrared and ultraviolet light, keeping the office cool. An overhang on the south side shades the windows from direct sun; on the east side, electrochromic glass controlled by a sensor darkens the windows when sun hits them directly and makes them transparent the rest of the day. Because the ceilings are high, the skylights bathe much of the office space in a diffuse light; in areas where the skylight illumination is too strong, Kaneda is experimenting with different types of diffusers.