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Efficiency Peak in the Rockies
Photograph courtesy Patrick H. Corkery, NREL
The U.S. government’s clean energy research team now works on a campus in the Rocky Mountain foothills that aims to showcase the promise for better buildings. With Colorado’s night air and intense sunlight helping to cool, heat and light the space for more than 800 workers, the new $64 million National Renewable Energy Laboratory (NREL) Research Support Facility uses half the energy of a more typical office building.
“It is, to our knowledge, the world’s most efficient building,” says Dan Arvizu, the laboratory director.
The H-shaped edifice in Golden, Colorado (map) is at the vanguard of an effort by the federal government—the largest single energy consumer in the U.S. economy—to prove that it is possible to use far less power, even with complex and diverse jobs to do. (Related: Overview Story) Following is a collection of U.S. government buildings that exemplify that efficiency drive, in many cases overcoming daunting obstacles with creative design.
NREL’s Research Support Facility, opened in June, houses the people who analyze U.S. research data on solar, wind, and other renewables, as well as advances in building energy. They also do the difficult job of moving that technology to commercialization.
The building’s long sides face north and south, allowing maximum daylight, while concave devices in the window glass reflect sunshine onto the white, highly reflective ceiling to provide diffuse, even light for all the building’s workspaces.
The ceiling also contains 42 miles (68 km) of plastic tubing, where cool water circulates in summer and warm water in winter. But the radiant cooling and heating gets a big assist from outdoors. Windows open to let in cool night air. For warmth, fans draw air in during the day through a transpired solar collector wall—an innovation developed by NREL’s own scientists. The perforated dark metal sheets capture enough solar energy to heat the air as much as 49ºF (9ºC) in the sunshine. Thick, heavy concrete walls and an innovative subterranean thermal labyrinth, or crawl space, beneath the first floor, help regulate the indoor temperature.
The building received the highest possible score in the U.S. Green Building Council’s LEED Certification program, and is expected to earn a Platinum rating later this year. But NREL senior engineer Otto van Geet says the building should be considered an “evolutionary” use of proven technologies, rather than a revolutionary facility that will be unique. “Every one of these strategies is very replicable, and many of them are appropriate for all buildings and all locations,” he says.
A Building Skin that Breathes
Photograph by Lee Foster, Alamy
A structure’s outer shell is traditionally known as the “building envelope,” but designers of the slender 18-story federal office tower at Mission and Seventh Streets in downtown San Francisco instead sought to surround the space with a “living skin” that opens to the elements.
With Bay Area temperatures hovering in a predictable 49º to 65ºF (9º to 18ºC) range year-round, it was an ideal location for natural ventilation. The cross-ventilation from the windows on the building’s northwest side and the glass curtain walls on the southeast side naturally cool about 70 percent of the space for the 1,700 federal employees who have worked here since 2007.
Bob Peck, now commissioner of public buildings for the U.S. General Services Administration, which manages the facility, remembers when the design idea first was floated near the end of the Clinton administration. “When the architects said they were proposing a building where most of the floors wouldn’t have air conditioning, we all kind of gasped,” he recalls. “Then, a couple of seconds later, we thought, ‘Why do they have AC in San Francisco, anyway? What have we been thinking?'”
Philip Haves, a building technology specialist at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, which modeled the natural ventilation for the building, says the San Francisco building’s strategy of pre-cooling the building structure at night could be applied in other climates. Although natural ventilation alone won’t suffice in humid regions that don’t cool much at night, Haves says much greater use could be made of passive cooling. “With care and forethought that starts right at the beginning of the design process,” he says, “in homes and office buildings, for example, you can substantially reduce, or even eliminate, conventional air conditioning energy use in many U.S. climates.”
Natural ventilation reduced projected cooling costs for the $144 million project by 86 percent—saving an estimated $500,000 in operational costs annually.
On the Roof: Postal Progress
Photograph courtesy Gerald Merna, USPS
There aren’t many places in midtown Manhattan to carve out a new 2.5-acre (1-hectare) park, but the U.S. Postal Service found a spot seven stories above street level—on top of the sprawling building where 12 million pieces of mail are sorted for New Yorkers each day.
Last year, the largest green roof in New York City opened atop the Morgan mail processing facility at Ninth Avenue and 30th Street.
(Related, from National Geographic Magazine, “Up on the Roof“)
The park—complete with benches, an art wall, and drought-tolerant native perennials—helps to cool the workspace for the 1,800 people who handle virtually the bulk of letters and packages delivered in Manhattan and the Bronx.
Air conditioning can be a major cost in a city facility with such a large workforce. So when it was time to replace the building’s black asphalt roof in 2007, the Postal Service began exploring ways to reduce the surface temperature. It turned out that the facility could support the weight of soil and vegetation, and would benefit in numerous ways from a park-like installation.
(Related, from National Geographic Magazine, Green Roof Photos)
The green roof is designed to last 50 years, twice as long as the roof it replaced. And the vegetation—including drought-tolerant ground covers like coral carpet, Immergrunchen, and John Creech—will suck down storm water. That will reduce runoff into the New York municipal water system by as much as 75 percent in the summer and 40 percent in winter, the Postal Service says. The Postal Service also was able to recycle and reuse 90 percent of the old roof in the new project.
Surrounded by a Healthy Commons
Image courtesy TVS Design
A greenscape with walking paths surrounds the curving 12-story Atlanta tower that is home to the U.S. government’s lead public health agency—a design meant not only to encourage physical fitness, but to save energy.
The campus of the $115 million headquarters of the U.S. Centers for Disease Control and Prevention, which opened in 2006, was planned to diminish the heat island effect that can grow oppressive in this hot Southern city. Tree-lined paths and permeable paving at ground level, sunscreens on the windows, and reflective roofing material all work together to take the edge off the Georgia sunshine for the more than 1,000 workers here. Also on the roof, a heat-exchanging energy recovery system cools incoming air in the summer, and warms it in the winter.
“The key to the success of this project was holistic approach,” says Micah Rosen, project manager, of the Atlanta architectural firm tvsdesign. The building features low-emissivity glass, made of a microscopically thin metal layered inside and outside the panes, to absorb sunlight and insulate. The rounded aluminum curtain wall allows maximum daylight to enter, while an indoor light management system dims artificial light when natural light is adequate for work activity.
The building, named for Senator Arlen Specter, the Pennsylvania Republican-turned-Democrat who formerly chaired the CDC’s budget subcommittee, is outfitted for a post-9/11 world with a large emergency operations center. The project budget included sitework, design, construction, commissioning, and equipment. Even with all the technology needed for agency officials to manage any type of public health crisis—from anthrax scare to flu outbreak—the headquarters is 20 percent more energy efficient than a typical office building.
History as the Outer Wrapping
Photograph courtesy Naval Facilities Engineering Command
The U.S. Navy’s first effort at green building was ambitious—remaking a structure near the Anacostia River in Washington, D.C., that was originally designed as a manufacturing shop in the decade before the Civil War.
Fittingly, the service’s own building engineers and designers—the Naval Facilities Engineering Command (NAVFAC)—are now housed in the very space they retrofitted in 1998. Known simply (in prosaic military style) as Building 33 in the Washington Navy Yard, the red brick structure is considered a model of the possibilities for energy-efficient renovation of an historic preservation site.
The Navy couldn’t make any changes to the exterior of the building, and had to take many steps to maintain its original character—a requirement of numerous overlapping authorities that oversee historic preservation in the nation’s capital. Case in point: All of the old, drafty, single-panel windows in the building had to stay intact. The solution: The Navy created a “super-window” effect, by installing double-glazed insulating glass on the interior side of the existing windows.
Indeed, because the edifice originally was a 45-foot-high (14-meter-high) open-bay factory, later used as a warehouse, the large open space was suited for a building-within-a-building. A four-story structure, with new insulated walls and roof assemblies, was constructed within the existing shell. It now provides office space for about 400 people, as well as a library, storage, and mechanical space.
The challenges were all worthwhile, says Michael Chapman, NAVFAC’s senior architect in the office of the Chief Engineer. “Using an old building is the greenest way to go,” he says.
All of the sustainable architecture features are estimated to have added just $85,000 to the cost of the $21 million project. With building energy savings estimated at $58,000 per year, the payback for the efficiency measures was less than two years.
Cooling Towers in the Desert
Photograph courtesy NREL
In a narrow slot canyon in the southern Utah desert, the National Park Serviceseized a chance to tap into the energy of a unique environment.
At Zion National Park in Springdale, Utah (map), where sandstone cliffs change in gradient from cream to pink to red against a cloudless blue sky, two downdraft cooling towers rise from the visitor center that opened in 2000.
(From National Geographic Travel: Zion National Park)
Desert heat evaporates water pumped onto a honeycomb media at the tower tops. Evaporatively cooled air falls through the towers under its own weight and gusts into the building. No fans needed. It’s an architectural feature that echoes not only the look of the scenery, but its cooling quality.
“We started looking at the climate,” says Paul Torcellini, principal group manager at the U.S. Department of Energy’s National Renewable Energy Laboratory, which collaborated with the park service on the project. “As you go up in the canyon, you get a lot of weeping water down the canyon walls that naturally evaporated and helped cooling.”
To help with heating (temperatures range from 20º to 60ºF (-6.6º to 15.5ºC) in winter), there’s a thick, dark sun-facing Trombe wall. Named for French architect Felix Trombe, who popularized the passive solar energy absorption technique, the wall gives off heat as the building cools, warming the building into the night. The visitor center also can fall back on electricity if needed, with a set of radiant ceiling panels that can provide heat. But together, the systems save more than 90 percent of the energy of a typical heating and cooling system—a savings of $16,000 per year.
The facility has transformed the experience for Zion’s more than 2.5 million visitors. Previously, on a typical summer day more than 3,000 private vehicles would traverse the two-lane road to a parking lot with only 400 spaces. Congestion not only hampered the visitor experience, it threatened wildlife and vegetation in the canyon. At the intersection of three separate ecosystems, it is home to 900 plant species not found anywhere else in Utah. Integral to the park’s design is a new shuttle bus system that runs on clean-burning propane. The $24 million cost of the project included purchase of the 30 buses and a bus maintenance center. Energy-saving features were incorporated into the building itself at a cost in line with that of a typical visitor center, says Torcellini.
(From National Geographic Travel: Zion National Park Photos)
Photograph courtesy U.S. Department of Energy
An expansive front porch gives the low, white Environmental Protection Agency building on Sabine Island, Florida, (map) the look of a Southern plantation. But in reality, it’s a computational and geospatial sciences (CGS) research lab, and the veranda is just one of the energy-saving features incorporated into the design.
The building, opened in 2008, houses about two dozen scientists in the EPA’s Gulf Ecology Division who conduct research on the impact of human activities on marine, estuarine, and wetland ecosystems. They help develop strategies to degrade toxic chemicals in the environment. Because their modeling work requires energy-intensive computer systems, the EPA worked to maximize energy efficiency by focusing on other areas of energy use, including cooling and lighting.
The light color and the large porch help deflect heat. And the building has numerous windows and skylights to reduce the need for artificial lighting. But all that glass posed a challenge for this location on a barrier island off the Florida panhandle. In 2004, Hurricane Ivan tore through Florida’s Gulf Coast, destroying six of the 40 buildings on the 16-acre campus where the CGS building now sits. So the many windows are made of high-impact glass, and aluminum was chosen as the primary roofing material because traditional shingles tend to come loose in tropical storms.
Water conservation also was an important concern in the design of the building on the fragile Gulf Coast. The building’s urinals and toilets use 100 percent recycled water gathered from a rainwater cistern on the roof. The building earned a LEED Silver designation from the U.S. Green Building Council.
“I think it’s important [to work toward sustainability] because it reflects our vision,” says Clay Peacher, facility manager at the EPA’s Gulf Ecology Division. “You’re walking the walk.”
Candace Adorka, Yewon Kang, Austin Lewis and Catherine Ngai are reporters for Medill News Service in Washington, D.C.
I’d like to return briefly to the topic of science, and explore further the difference between “science” as in “what researchers do” and Science (with a capital “S”) as in “what researchers have told us.” The first is a way that we …
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City Forest, Singapore
Photograph by Wong Maye-E, AP
Using plants and trees in a unique way, Singapore officials opened Gardens by the Bay this year. The 11-million-square foot (1-million-square-meter) complex—the size of nearly 250 U.S. football fields—aims to curb the heat island effect while bringing botanical bliss to urbanites.
The centerpiece of Gardens by the Bay is a glass atrium that houses approximately 220,000 types of vegetation, or 80 percent of the world’s plant species, according to Singapore’s National Parks Board.
Outside the menagerie of plants is a grove of 18 “supertrees”— vertical gardens up to 164 feet (50 meters) tall that capture rainwater, filter exhaust, and are capped with solar panels that provide enough energy to light up the trees at night.
The heat island effect occurs in cityscapes characterized by pavement, asphalt, and concrete—all materials that can absorb warmth. The annual mean temperature of a city with one million people or more can be up to 5.4°F (3°C) warmer than surrounding rural areas, according to the U.S. Environmental Protection Agency (EPA). The effects cascade as summertime peak energy demands rise along with air conditioning costs and greenhouse gas emissions.
(Test your A/C acumen with our quiz: What You Don’t Know About Air Conditioning.)
The value of vegetation in urban areas goes beyond cooling and shade. City plantings can also help improve air and water quality through filtering mechanisms.
A new study in the journal Environmental Science & Technology shows that grass, ivy, and other urban plantings, in addition to trees, can reduce levels of nitrogen dioxide and particulate matter by as much as 40 and 60 percent respectively. Both are pollutants that are potentially harmful to human health.
(Read more about the water quality benefits of vegetation in National Geographic News’ “Philadelphia Cleans Up Storm Water With Innovative Program.”)
Greening Government Buildings, Berlin
Photograph by Robert Wallis, Corbis
The Reichstag, Germany’s parliament building, was retrofitted in 1999 with a new dome that uses glass and mirrors to reflect daylight deep into the main chamber, reducing dependence on artificial lighting. It also employs a funnel to divert and collect rainwater.
Designed by British architect Norman Foster, the renovated Reichstag has become a Berlin tourist attraction and an energy saver.
The dome-reflector system also draws warm air out of the building. This feature, combined with the fact that the building can make its own electricity from refined vegetable oil, as well as store excess heat underground, brings the building’s carbon dioxide (CO2) emissions down by 94 percent, according to the architect.
Green buildings have myriad benefits, including reductions in greenhouse gas emissions, water use, and toxic materials use, improved air and water quality, and relief from the heat.
In the U.S. there is a debate brewing on Capitol Hill about how to define a green building.
The U.S. government requires all new federal construction to follow the U.S. Green Building Council’s (USGBC) requirements for a gold rating.
USGBC ratings—certified, silver, gold, and platinum—are awarded based on several factors, including sustainable site development, water savings, energy efficiency, and materials selection.
But, to the disappointment of some chemical and plastics companies, the USGBC’s rating system is expected to change next year and may discourage builders from using some products such as PVC piping. A coalition of chemical and plastics manufacturers is lobbying Congress to use another set of criteria.
(See how the U.S. government has gone green in National Geographic News’ “Pictures: Seven Supergreen U.S. Government Buildings.”)
Floating Food, New York
Photograph by Tyrone Turner, National Geographic
The Science Barge is a floating environmental education classroom and greenhouse on the Hudson River in New York.
Fueled by solar power, wind, and biofuels, the barge, which was built in 2007, has zero net carbon emissions.
Vegetables are grown hydroponically—with plants getting all of their necessary nutrients from water instead of soil—in an effort to preserve natural resources and adapt to urban environments, where healthy soil, or soil at all, is hard to come by. Rainwater and treated river water are used for irrigation, and pesticides are prohibited.
The original owner of the barge—New York Sun Works—designed it as a prototype for closed-loop and self-sufficient rooftop gardens in urban areas.
(See more pictures of urban agriculture in “Urban Farming Is Growing a Green Future.”)
Thousands of schoolchildren and adults have visited the barge, which is now operated by Groundwork Hudson Valley and docked in Yonkers, just north of New York City.
Sustainable Housing, Denmark
Photograph from Yonhap News Agency/European Pressphoto
There are no official global standards for green buildings, but hundreds, if not thousands, of examples of sustainable construction are found internationally.
8 Tallet—Danish for 8 Houses—surpasses the capacity of most other green housing developments in Denmark, and the world.
Designed by the Bjarke Ingels Group, the suburban housing development—about a ten-minute train ride outside of Copenhagen—has nearly 500 apartments and incorporates a commercial district, so that residents don’t need to burn fossil fuels to shop for groceries or lounge at a cafe.
The buildings, officially opened in 2010, are oriented to capture as much daylight as possible, and an elaborate 18,000-square-foot (1,700-square-meter) green roof helps to deflect harsh rays and keep the grounds cool. Traditional tar-based or black urban roofing materials contribute to the urban heat island effect by absorbing heat and raising city temperatures.
Solar Dominance, China
Photograph by Liang Baohai, Imaginechina/AP
The Sun-Moon Mansion is headquarters for what could become the biggest solar energy production base in the world, or the Silicon Valley of solar.
The office building, conference center, and training facility is the home of Himin Solar Energy, the world’s largest maker of solar water heaters. The company was founded by oil equipment engineer Ming Huang, a member of China’s Parliament known as the “Sun King.” Huang has expressed concern about a fossil fuel-dependent economy, and is working to transform the area around the Sun-Moon building into China’s Solar Valley.
The 807,000-square-foot (75,000-square-meter) headquarters also features insulation techniques that will help the structure achieve energy savings up to 30 percent higher than the national standard.
China is on a mission to meet 15 percent of its energy needs with renewable sources by 2020. The country is currently at 9 percent.
Photograph by Marco Bulgarelli, Gamma-Rapho/Getty Images
It takes a village … to truly go green. Quality of life and sense of community are key at the BedZED eco-village in London. Private developers completed the mixed-use community in 2002, making it the first such community in the United Kingdom. The village comprises a hundred homes and enough office space for a hundred workers.
With a rooftop garden, reclaimed building materials, efficient insulation, solar panels, ramped up recycling rates, and a very short commute, BedZED residents reduce their carbon footprint by nearly 50 percent, according to development partner BioRegional
Air Tree, Spain
Photograph from Art on File/Corbis
“Air trees” in the Madrid suburb of Vallecas are self-sufficient gardens that produce excess oxygen and energy.
Made from recycled materials, the air trees provide respite from summer heat with shade and natural ventilation. Solar energy collected by photovoltaic panels on the trees’ canopy is used to power sprinklers and other aspects of plant maintenance. Additional energy is fed back into the region’s electrical grid.
The trees were first installed in 2007.
(Read more about vertical gardens in National Geographic News’ “High-Rise Farms: The Future of Food?”)
Wind Tower, Abu Dhabi
Photograph by Ali Haider, European Pressphoto Agency
The Masdar Institute wind tower, just southeast of Abu Dhabi, is part of a planned city being built by the Abu Dhabi Future Energy Company with the help of government funding.
British architects at Foster + Partners aim to create a city that is 100 percent powered by renewable energy technology and produces zero waste. Masdar City, when completed, will be the “global center of future energy,” according to developers.
The wind tower circulates cool, carbon neutral, air throughout the grounds of the Masdar Institute of Science and Technology.
Low Carbon Campus, United Kingdom
Photograph by Ashley Cooper, Corbis
The section of England’s Northumbria University called City Campus East was one of the first buildings in Europe required to meet new green standards coming out of the United Nation’s 1997 Kyoto Protocol to reduce greenhouse gases and combat climate change.
Opened in 2007, City Campus East provides housing for up to 9,000 students. In 2011, the building won the title of Low Carbon New Build Project of the Year—an award handed out by the U.K.-based Chartered Institution of Building Services Engineers.
An Eco-Village, United Kingdom
Photograph by Matt Cardy, Getty Images
The Wintles estate in Shropshire, England, may look like your average suburban housing development, but the homes here are among the most energy efficient in the U.K.
Houses, apartments, and other residential dwellings account for just under 30 percent of the country’s carbon emissions, so the government is encouraging people to live in eco-villages such as Wintles.
Photograph by Diane Cook and Len Jenshel