By Julie Eisele
Sustainable building products and practices are increasingly mainstream in the United States, as designers and builders show greater appreciation for the benefits of resource conservation, improved health and productivity of occupants, and, in many cases, lower operation costs.
The green building concept originated with such basic practices as double-glazed windows, energy-efficient lighting installations, and bulkier insulation. Over time, architects and engineers began to scrutinize virtually all systems, looking for ways to save natural resources yet maximize performance, and create healthier environments for occupants.
“We should create buildings that do the least harm to the environment. The ultimate sustainable building would be one that cleans the air, rather than pollutes it,” says architect Kristian Kicinski of Bassetti Architects in Seattle. “That’s an ideal at this point, but it’s something we strive for.
“Why should we do the least harm? Because the more data we collect, the more we understand that buildings that are good for the environment are good for the people using them, too. Green buildings are high-quality buildings.”
One sign of progress is the large number of eco-friendly building products on the market. They run the gamut from flooring to windows to mechanical systems to exteriors. Manufacturers are reflecting the demands of design and construction professionals, says Max Zahniser of the U.S. Green Building Council (USGBC).
“The product market is one of the easiest ways to measure transformation toward green building, and we have seen a lot of progress with the product lines,” says Zahniser, who is the council’s LEED new construction certification manager.
Transforming the industry’s marketplace so that sustainable practices become routine is a goal of the USGBC. The council, based in Washington, D.C., brings together members of the building industry and the environmental movement to focus on sustainability issues. The USGBC also oversees the LEED (Leadership in Energy and Environmental Design) green buildings rating system. LEED is a set of voluntary criteria that enables projects to be certified as high-performing, green facilities.
The LEED program has spurred much of the growth in the building products industry in the United States, Zahniser says.
Still, sustainable products and technologies continue to evolve into new - even futuristic - directions. Architects are paying attention to biomimicry, a science in which nature’s ideas are studied and then imitated - such as the adhesive capabilities of mussels, which may offer insight for creating effective but nontoxic adhesive materials. The self-cleaning trait of the lotus plant is also analyzed, as researchers seek ways to keep surfaces clean.
Building-integrated photovoltaics (BIPV) is a technology that will grow rapidly in coming years, according to the U.S. Department of Energy (www.eere.energy.gov). Solar photovoltaic (PV) panels transform sunlight into electricity. PV technology generates power on-site. The BIPV concept includes the integration of photovoltaic modules into a facility’s roof, windows, or exterior skin, allowing them to serve as the building envelope while also producing power for the facility.
Manufacturers offer numerous exterior cladding options that function to capture useable energy, such as SolarWall™ panels, which are a key design element in The West Metro Education Program (WMEP) Interdistrict Downtown School (IDDS) in Minneapolis. The panels were installed on the magnet school’s south face, designed to absorb heat from the sun and preheat intake air in the winter (www.solarwall.com). The school’s design team established a list of goals that focused on sustainability issues, says Janet Dray, a senior interior designer at Cuningham Group, Minneapolis.
Lighting needs were met by partnering daylight with electronic lighting controls; fixtures near the windows dim when sufficient daylight is present, thanks to photoelectric light sensors and dimmable ballasts (www.hew.com, www.advancetransformer.com). The school’s mechanical systems, data lines, and fire sprinkler lines are color-coded and exposed so that students can learn about them as part of the emphasis on “experiential” - or hands-on - learning. “The building itself is a learning tool for students,” says Dray.
Site selection can affect product selection - and can even limit the need for some resources. IDDS partnered with the city of Minneapolis to build the 600-student school atop a below-grade parking ramp. Its strategic location facilitates alliances with various educational facilities and libraries, art and science institutions, and businesses. Its close proximity to the YMCA meant there was no need to build a gymnasium.
But site selection is not always a factor that is in the builder’s control. Still, says Heather Rosenberg, a sustainable design consultant, it is important to use the resources on the site.
“You make the building fit within the context. What is the climate? What are the heat loads and cooling needs? Can we catch and use outdoor breezes? Part of ‘green building’ is that there isn’t just one answer. We look for strategies that use the least amount of energy over time,” says Rosenberg, who works at CTG Energetics Inc., a consulting-engineering company in Ivrine, CA.
An obvious approach is the use of daylighting. Clerestory windows and integrated lighting controls are growing in popularity. These windows are located high on the building, designed to provide daylight, reduce lighting needs, and ultimately reduce energy use.
“Clerestory windows are great because they bring out the daylight, and they can be integrated with automated lighting systems,” says Rosenberg.
At the Carnegie Library of Pittsburgh, Brookline branch, clerestory windows provide filtered light into reading areas and into the entryway. A unique “light wall” was also created, providing natural light all the way to the library’s basement, says Jennifer McCarthy, an architect at Loysen + Kreuthmeier Architects in Pittsburgh. The firm was asked to help transform and expand the two-story concrete block library. Before construction, the basement was used for storage. Upon completion, the library’s space doubled - the basement was transformed into useable areas - yet energy costs remained the same.
The light wall provides luminosity to several floors of the building due to architectural features that bounce and reflect the light into interior spaces, notes McCarthy. A 4- by 42-foot opening was created along an exterior wall of the first floor, allowing light to filter down into the basement. Floor joists were left in place, and a railing protects library patrons. The library’s energy efficiency can also be attributed to improved insulation that was added to exterior walls and to the roof.
Interior products were carefully selected, says McCarthy. For example, the team chose linoleum from Forbo Flooring (www.forbolinoleumna.com), manufactured with renewable products such as linseed oil, a product of the flax plant. Linoleum is gaining popularity because of indoor air quality issues; there are no chemical agents used in manufacturing linoleum, and it emits lower levels of contaminants than some other flooring options. The library’s project team has applied for LEED certification.
CTG’s Rosenberg says her clients are showing interest in environmentally preferable materials, such as composite wood with low levels of volatile organic compounds (VOCs), rapidly renewable materials like bamboo, and products made from waste agricultural materials, such as insulation made from recycled cotton waste from denim manufacturing. Strategies that avoid using materials, such as sealing concrete instead of installing flooring, are also gaining interest.
“There is a big market for green interior products. We are moving toward low or zero VOC paint, low-emitting carpet, sustainably harvested wood, finish materials made from recycled content, and others,” Rosenberg notes.
In the Minneapolis magnet school project, restroom tiles were comprised of 80 percent recycled materials, and WheatBoard™, a biodegradable agricultural byproduct, was used for cabinetry and some tabletops (www.primeboard.com).
Dakota Burl™ is a similar product, selected for some of Seattle-based Boxwood Architecture’s projects (www.environbiocomposites.com). Used for tables or countertops, the wood product is made from renewable agricultural fiber, according to project manager Karen Davis Smith. “We look for products that last longer and provide healthier buildings - materials that do not contain VOCs or off-gas, and which cause the least damage to the environment.”
Sometimes, product choices are based on vendor commitment to the environment. “We purchased some Herman Miller furniture because they use blankets to wrap and transport the furniture, not boxes,” says Loysen + Kreuthmeier’s McCarthy (www.hermanmiller.com). “They take the blankets with them, and reuse them after they move the furniture.”
And finally, no building is complete without a roof. “Green roofs” are fairly common in some European countries and are drawing more interest in the United States. Rooftop vegetation reduces storm water runoff, absorbs and/or deflects solar radiation, and provides insulation. Planted roofs can help prevent urban heat islands and provide a habitat for birds. Intensive green roofs are garden-like, providing space for people and often requiring irrigation. Extensive green roofs are typically built with self-sustaining plants that require minimal maintenance and are not usually areas that are used by people.
But vegetative roofing is not an option routinely selected. In situations where a more typical roof is sought, white thermoplastic polyolefin (TPO) roofing membranes can be a good choice for sustainability. Studies show that white reflective roofs can reduce cooling needs substantially when used in roofing retrofit projects, according to Sarnafil, which manufactures the EnergySmart Roof® membrane (www.sarnafilus.com).
While sustainable design and material selection are decidedly more conventional, industry experts acknowledge that resistance is not uncommon. “The green building industry has been experiencing exponential growth, but we still have a long way to go to reach our broader sustainability goals,” says Rosenberg.
“There is a perception that sustainable design costs more. Sometimes it does cost more,” says Boxwood’s Davis Smith. “But they tend to cost less over time, in terms of energy savings, design flexibility, and productivity.” Sustainable design is synonymous with high-quality design, adds Bassetti’s Kicinski. “Green buildings are just better buildings, any way you look at it,” he says.
Many architects estimate that green building practices boost total costs by 2 to 3 percent, and sometimes as high as 8 percent for higher end projects, according to Kicinski. Costs are usually recouped in the areas of energy efficiency and maintenance, he notes. “In many cases, you can substitute a material that is renewable or recycled that won’t necessarily cost you more,” adds Dray, of the Cuningham Group.
Sometimes resistance can be overcome with a bit of education.
“Most people who are learning about [green building] are deciding that it’s worthwhile,” says the USGBC’s Zahniser.