Building to the Future
By Tom Yulsman
Helped along by climate change, the mountain pine beetle — an insect no larger than a grain of rice — has now managed to cause the widespread death of trees across more than 8.8 million acres of U.S. forestlands in the West, according to the U.S. Forest Service. That acreage is an area more than twice as large as the region’s most iconic national parks: Yosemite, Yellowstone, and Grand Canyon.
In Canada, the infestation is even worse, with more than 43 million acres of British Columbia affected to one degree or another.
It’s a depressing tally. But for the interior designers of the National Renewable Energy Laboratory’s (NREL) new office building in Golden, Colorado, the beetle scourge was also an aesthetic and symbolic opportunity.
To realize that opportunity, the designers lined the entrance of NREL’s new Research Support Facility, or RSF, with paneling made from wood killed by the pine beetles. The wood is streaked with an arresting blue stain caused by a fungus deposited by the beetles when they bore into a tree to mate and deposit larvae. A tree ordinarily tries to defend itself with a flow of pitch to ward off attacking beetles and kill their larvae. But the fungus blunts this defense, and also blocks the flow of water and nutrients within the tree — typically, with fatal results.
Use of the beetle-killed wood in the new building’s lobby saved living trees from the axe. “It also meant removing dead fuels from the forests that could have otherwise helped sustain wildfires,” says Allison Menke of RNL Design, the firm that did the architectural, landscape and interior design of the building.
In this way, the paneling symbolizes the goal that drove the design of the facility: construct one of the most environmentally friendly and energy efficient office buildings in the world.
There was also deeper symbolism in the choice of the wood, one that went beyond its immediate environmental value. Scientists believe warmer winter temperatures in the West have boosted survival of pine beetle larvae from year to year, at the same time that drought has lowered the trees’ defenses. In this way, global warming has given a strong boost to the diminutive insects’ assault on forests.
So the subtle yet eye-catching blue streaking in the wood paneling signals the reasoning behind the building’s innovations — and offers a compelling argument for why many more buildings just like it will have to be built in coming decades
In Menke’s view, the design of these structures must address one simple and clarifying question: “How can we make buildings react to their environment in a more responsive way?”
The need to do just that is clear. In part because it involves the use of known technologies, improving the energy efficiency of buildings is viewed as low-hanging fruit in the battle to reduce greenhouse gas emissions that are contributing to global warming.
According to NREL senior engineer Michael Deru, commercial buildings now consume 72 percent of the nation’s electrical production and 39 percent of its total energy. In addition, they are responsible for 40 percent of all raw materials used, and 14 percent of potable water.
In 2008, commercial buildings produced nearly 20 percent of U.S. greenhouse gas emissions — a tally equal to the emissions of a number of individual countries and even entire continents, including Japan, India, Africa and South America, according to Deru.
“That’s kind of scary to me. Just the commercial buildings in the U.S. are responsible for more emissions than all of India, with its 1.2 billion people,” Deru says.
“Luckily, our commercial buildings today are really bad, so there’s lots of potential for making improvements,” he notes wryly.
NREL’s Research Support Facility was designed to show how far those improvements could be taken — without spending a fortune.
The goals were ambitious. “The workplace of the future was what NREL had in its contract — literally,” Menke says.
In addition to achieving “net-zero status” — meaning the building would generate all of the energy it needed — NREL wanted a facility so environmentally friendly that it would receive LEED Platinum certification. LEED stands for “Leadership in Energy and Environmental Design,” an internationally recognized certification system developed by the U.S. Green Building Council.
To receive LEED certification, a new building is evaluated on factors that include the environmental suitability of the site, reduction in water and energy consumption, cuts in waste production, use of recycled and sustainably produced materials, improved indoor air quality — and the list goes on.
To achieve Platinum status, the highest certification in the LEED system, and also to enable solar panels to produce enough electricity to affordably supply all of the facility’s power needs, NREL’s new building would have to reduce energy consumption per square foot by about 50 percent below minimum performance targets in heating and cooling, according to Gregory D. Collette, a project officer for the Energy Department. The designers would also have to reduce the use of virgin materials, such as steel made from newly mined iron, and waste generated during the building’s construction.
And there was a higher order goal as well, Deru says: “Apply research, development and deployment to change industry and move the market.” Within the Department of Energy, “the focus is now on speed and scale — how fast can we make an impact, and how big can that impact be?”
That’s a lot riding on one 220,000 square-foot office building. To accomplish these goals, planners realized that the normal process of separating the architectural design of a building from its engineering and construction would not work. Instead, both were combined in a “design-build” process, in which engineers determined what was necessary to achieve the required energy and environmental improvements, and then architects tailored their design to fit within those constraints.
From "daylighting" to the "Labyrinth"
The beetle-killed wood in the lobby wasn’t the only recycled material used in construction of the building — or the only design choice with environmental symbolism. In fact, the entire building is held up by steel recycled from the fossil fuel industry: decommissioned natural gas pipelines cut into sections and repurposed to serve as the support columns.
This early photo shows the first few reclaimed gas pipes being erected at the RSF construction site. Using these recycled pipes has helped the building attain LEED Platinum status. Credit: Carl Cox/NREL.
Similarly, concrete dug up during the demolition of Denver’s now-closed Stapleton Airport was used as material in the building’s foundation.
Some of the waste material generated during construction was recycled for use in various applications in and around the building. For example, rock dug out to prepare the building’s foundation was poured into cages made of recycled steel to form outside retaining walls.
All told, about 20 percent of the material in the building is made from recycled content. And 75 percent of all the waste generated during construction was actually used in various ways, and thereby kept out of landfills.
Completed in June of 2010, the building is designed for about 800 workers. From the outside, it’s obvious that this is no conventional office building. The RSF is built in the form of a skewed “H.” Two long narrow wings (one three stories high and the other four) are joined in the middle by a short connecting space that contains the lobby and conference areas.
The narrowness of each wing — just 60 feet wide — enables natural light from banks of windows to easily reach the interior office spaces. Called “daylighting,” this approach “offers a huge energy savings potential,” says Rob Guglielmetti, part of NREL’s Commercial Buildings Research Group. That’s because 30 percent of all energy use in a typical commercial office building goes toward lighting.
As a former lighting designer for museums, Guglielmetti says he used to specialize in keeping natural light out of interior spaces. For his work on the RSF, he reversed those skills, findings ways to bring as much natural light as possible inside the building — but without causing excessive heat loss or gain through the windows.
Among the innovations he and his colleagues devised were fixed, reflective Venetian-blind-like slats on the upper aspect of windows on the sunnier south side. These metal slats reflect light from outside the building up toward the ceiling. Painted a bright white, ceiling panels reflect this light into the interior.
To further ensure that daylight penetrates deep into the office spaces, the walls of the cubicles are only about waist high, creating an open, airy work environment. Each desk comes with a small LED task light, and ceiling lights are on light sensors, so they turn on only when needed.
To prevent excessive heat gain from intense afternoon sun — and thus electrical use for cooling — “electrochromic” glass that tints a cool blue at the flip of a switch is used on broad expanses of windows on the building’s west side.
To realize significant savings in heating and cooling, the building’s designers reached back to the cathedrals of the medieval era. The massive stone walls of these soaring structures store solar heat much like a battery stores electrical energy, releasing it slowly into the interior to help keep the building warm during winter.
The RSF’s designers came up with a modern twist on this ancient engineering practice: Place thousands of tons of concrete in the basement to serve as a thermal battery.
Here’s how it works: Winter air heated by sunlight beating down on the building’s south side is drawn through perforated metal panels and delivered to a shallow basement. Here, the solar-heated air is supplemented with waste heat from NREL’s computer center, and passed through a maze of concrete structures called the “labyrinth.”
Like cathedral walls, the concrete absorbs the heat. At night and the next morning, air circulated through the labyrinth is thereby warmed five to 10 degrees and then piped into the building to reduce the demand on the heating system.
During summer, the system works in reverse: Cool nights chill the labyrinth, helping to reduce cooling costs during the day.
Electrical use was cut in many other ways as well. Instead of desktop computers, most office workers work on power-sipping laptops. When extra fresh air can help save on cooling costs, a little message pops up on some of those laptops alerting workers to open windows near their desks. (And every third window can open automatically when necessary.)
Light bulbs in vending machines are disabled. Ice machines are plugged into programmable outlets so ice isn’t made when workers aren’t in the building. The cleaning crew does its work during the day, saving yet more on lighting costs. And even the little LED lights on the office phones were programmed to turn off when the devices are not in use.
“NREL workers have experienced a big shift in the culture of their office,” Menke says.
Daylighting in the RSF. Credit: Tom Yulsman.
“It’s very different,” says Irene Passage, an administrative assistant. “But I like it. The air is clean and it’s a very serene place.”
With the big, open workspaces, privacy is an issue. So the designers made sure to incorporate “huddle rooms” — small, walled conference rooms where workers can go when they need privacy.
Beth Schafer, another employee at the RSF, used to work at a building NREL rented nearby. “I was in an enclosed office there,” she says. “The RSF is different. I like the ambiance, the open feel. And it’s actually very quiet even with the short cubicles.”
Schafer even likes the stairwells, which are daylit just like the office spaces. “This encourages us to take the stairs,” she says — which, of course, further reduces electrical use.
Have Ambitious Goals Been Met?
Since the RSF opened, every aspect of the building’s performance has been monitored closely, according to Guglielmetti. “So far,” he says, “the building is performing just the way computer simulations said it would. It’s doing quite well.”
To illustrate just how well, he compares it to the Environmental Protection Agency’s Region 8 LEED Gold certified office building just down the road in Denver. “It is often held up as an exemplar green building — and it is actually using almost twice as much energy per square foot as the RSF.”
When calculated another way, the building’s energy use works out to 300 watts per person at any given time, according to NREL’s Chad Lobato, who has been involved in the monitoring effort since the facility opened. “This is equivalent to having each occupant leaving five 60 watt light bulbs on 24/7,” he says. And that’s enough power for everything — the laptops, the servers, all lighting, heating, cooling, ventilation and anything plugged into electrical outlets.
How much extra did U.S. taxpayers have to shell out to achieve these efficiencies and other environmental benefits? “There was no cost premium for constructing this high performance, energy efficient building,” Guglielmetti says. Per square foot, construction costs amounted to $259, which is about in the middle of the cost spectrum for energy efficient office buildings in this region.
Thanks to the energy savings, it became feasible, both technologically and financially, to produce all of the energy needed on site. Heating for the building and other nearby NREL facilities is supplied by a renewable fuels heating plant on the lab’s 327-acre campus, which burns chipped beetle-killed wood. Meanwhile, solar panels provide electricity.
NREL expects the building to achieve net-zero status by early next year, when all 1,800 photovoltaic panels will be in place, cranking out a total of 1.6 megawatts of electricity. Many are already erected on the RSF’s roof; more will be placed on an addition to the building and a parking structure now under construction. (To save on up-front solar costs, NREL entered into a power purchase agreement with Sun Edison.)
Gregory Collette, DOE’s project manager, says his agency is eager to help others learn from the RSF’s environmental achievements. “We’ve got the building now,” he says, “so we can show that it can be done.”