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Specifying Sustainability

How do architects define true sustainability?
By Kim A. O'Connell

Imagine the sustainable building industry refashioned as a game show called Global Jeopardy. After racking up points by selecting green products, you and two other contestants are down to the final question: "Which roofing material is the most sustainable?" "Recycled rubber tiles," answers one competitor. "A vegetative green roof," declares the other. "Good old-fashioned slate," you say. The clock ticks. The earth hangs in the balance. Finally, with great fanfare, the host announces that all three answers are correct and everybody wins. How is this possible?

When considering sustainable products and materials, architects, builders and designers are faced with more choices than ever before. As just one barometer of the sustainability trend (albeit a major one), the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) rating system has become extraordinarily popular, representing nearly 50,000 accredited professionals, more than 10,000 registered projects (and about 1,300 certified), and more than $12 billion in value to the construction industry. As sustainability has gone mainstream, the green-building market has been flooded with products and materials.

"Architects are being inundated with all sorts of claims from every supplier about how green their product is," says David Vottero, AIA, LEED, the director of architectural design for Columbus, OH-based Schooley Caldwell Associates. "People come here and say if you spec my product, you get this or that LEED point, but sustainability is a holistic approach, and it's difficult to single out one thing like materials. There ought to be an integrated approach to design and material selection and specification."

So how do architects and other designers wade through the growing list of available green products and materials? Generally, it comes down to durability and lifecycle factors, energy efficiency and embodied energy, recycled content and salvaged materials, third-party certifications, and how sustainability fits into a project's overall mission and design.

Durable Goods
Few places in Maryland are more historic than St. Mary's City, the state's former colonial capital established in 1634. At its heart is St. Mary's College of Maryland, a campus whose stately brick buildings evoke the local heritage but which exudes a very modern commitment to environmental technology. Its newest building, Goodpaster Hall, is the first LEED-certified building on campus, recently earning a silver rating. Designed by Washington, DC-based SmithGroup with red-brick cladding and simple geometry, Goodpaster Hall features such products as lumber from sustainably harvested forests, waterless urinals, and rainwater and greywater systems that recycle water from sinks for flushing. About 75% of the building materials are made with recycled content, including structural steel, drywall, carpeting and laboratory counters.

Goodpaster Hall is, in many ways, a green manufacturer's dream project, yet its designers also sought to use products that were durable and less likely to need frequent replacement. "You're always trying to strike this balance between breaking new ground – and green products tend to be new – and choosing those products that you don't generally think of as being green but really are green," says Greg Mella, AIA, LEED, a principal with SmithGroup. "Selecting materials for the St. Mary's job, we looked at the exteriors on the campus, which were all brick and slate, and they are typical green materials. They tend to be locally manufactured products with low embodied energy. Then we weighed that against the fake slate made of recycled rubber, and it doesn't have the life span, and it has a higher embodied energy."

Several architects interviewed for this story agreed that inert, natural materials and products such as stone, brick and cements were intrinsically sustainable because they are durable, with low embodied energy and a high potential for reuse. But Mella isn't saying that the recycled rubber roofing couldn't be perfect for a different project – the point of sustainability is to balance the impacts of every decision against every other one. "There are so many sustainable products out there, and you can do a building that looks like anything you want and features anything you want," he says. "We try to look at the duration and life span of a material, how it is maintained, and how much energy goes into the manufacture of that material."

Lifecycle analysis is critical to front-end decision making, Mella adds. "I do a lot of my work in higher education and happily, campuses are looking for long-life buildings, 50 years or more," he says. "Students inhabit these buildings, so they have to be resistant to students swinging bats and standing on desks."

"Life expectancy is a very important factor," agrees John H. Cluver, AIA, LEED, director of historic preservation for Voith & Mactavish Architects in Philadelphia, PA. "Buildings that are well built and well designed will be well used and well loved far into the future. The materials need to be able to last, which includes being able to be maintained and repaired. There are countless stories of historic buildings that have found a second life with an entirely new function, where the main reason these buildings were saved is because they were so well built that they were going to be difficult to demolish. The fact that these buildings were built with the expectation of a long life allowed them to have that long life."

Cluver's firm is now working on a school building (a project so new he is reluctant to divulge details for publication) in which the architects opted for slate flooring, stained concrete corridors and metal roofing instead of less-durable materials. "They had a much higher initial cost, but will pay for themselves with their low maintenance needs and absence of a replacement cycle," he says. "This same project also spent extra on high-efficiency glass, efficient lighting, and a roof with low heat absorption, all of which will save the school money on energy costs every year."

Conserving Embodied Energy
In Omaha, NE, a sustainable "concept house" for the U.S. Department of Housing and Urban Development's PATH program (the Partnership for Advancing Technology in Housing) is a show horse of sustainable product specification. The house contains recycled-content carpeting, as well as flooring, plaster, paint and even furniture designed to emit low quantities of volatile organic compounds (VOCs). To conserve energy, more than 80% of the lighting in the house is of the compact fluorescent variety, and other light fixtures are either low-voltage or rated under the federal government's well-known Energy Star program.

Yet focusing on only green products misses the whole point of sustainability, says Fernando Pagés Ruiz, a Lincoln, NE-based home builder who built the Omaha PATH house. He is also the author of "Building an Affordable House." "There is a lot of attention paid to individual products, which is kind of a hodgepodge approach," he says. "It isn't an energy-efficient house just because you stick an energy-efficient furnace in it." Energy efficiency also derives from the durability of the exterior cladding materials, which will preserve the energy embodied in their manufacture and installation, and the flexibility of the interior spaces to be adapted to new uses. "Part of the sustainability of this house is the ability to change it without doing a major demolition," he says. "There's an ecology to efficiency, to quality, to using less materials."

The concept of embodied energy has been one of the most difficult for the design and building industries to quantify and understand. We all can grasp the connection between installing fluorescent bulbs and a lower utility bill. However, it is much harder for designers to estimate the energy that goes into manufacturing a particular product or material, how that factors into the cost estimates for a project or the lifespan of a building, and the energy that is expended when that material is disposed of later or recycled into some new product. "The industry as a whole does a poor job of determining true sustainability," Cluver says. "It is very easy for a manufacturer to claim that its product is sustainable in some way and very difficult to verify these claims. For example, I could claim that new insulation vinyl windows are sustainable, by focusing on the reduction in heat loss compared to a single-glazed window… This, however, ignores the energy required to produce these windows, their lack of durability and recyclability, and the ability to achieve comparable energy savings through window repairs and a storm window."

That said, Cluver believes that the greatest innovations in the sustainable design field are related to energy – either producing it (through photovoltaic panels, wind farms or alternative fuels) or conserving it (through more streamlined operations, improved thermal efficiency and recyclability). He hopes that future iterations of LEED continue to reflect the industry's growing recognition of embodied energy, not just in existing structures but in the materials used to restore buildings or construct new ones.

Recycled and Renewable
If ever there was an apt name for a building, the 19th-century Lazarus department store in Columbus, OH, may be it. Like the biblical Lazarus who was raised from the dead, the one-million-sq.ft. landmark was recently restored and adapted as a mixed-use facility, including offices, retail, exhibition space and restaurants. Sustainably designed by Schooley Caldwell Associates, the project (certified gold under the LEED system) features an array of recycled-content products, including terrazzo flooring made with recycled glass, toilet partitions fashioned out of recycled plastic bottles and flooring made from old tires. Readily renewable materials such as bamboo flooring and cork baseboards were also employed.

Indeed, one of the clear successes of the sustainable-design movement has been the proliferation of recycled-content products, but some say that has given designers an overly facile way to go green. "Recycled content is a good thing, but it's a double-edged sword," says Schooley Caldwell's Vottero. "I assign less value to recycled content than to other considerations, because sometimes manufacturers are using materials with a lot of embodied energy. Take recycled plastic timber: How many milk jugs were used to make that bench? When you think about the amount of petroleum products that went into those milk jugs, is that a good investment for the materials? Sometimes it's just downcycling."

Although Vottero is optimistic about the forthcoming LEED version 3.0, he believes the current rating system places too much emphasis on recycled content. "Recycled content is the low-hanging fruit [of the LEED system]," he says. Here, as with lifecycle analysis and embodied energy concerns, design professionals must take a more profound approach to the products they specify. Manufacturers still confuse the marketplace, Vottero says, and remain fuzzy about the extent to which they are incorporating post-industrial versus post-consumer recycled content – the former being simply the manufacturing equivalent of kneading together leftover dough to make more biscuits. Harnessing post-consumer recycled content is considerably more difficult and expensive.

Renewable materials pose challenges of a different kind. Even when specifying natural materials like wood or plants, architects and landscape architects may find that there is more (or less) than meets the eye. "Unfortunately, the quality of some materials has declined, the prime example being wood," Cluver says. "The quality of wood today is not as high as it was 100 years ago, due to historically poor resource management requiring the use of fast-growth lumber that is not as durable." Tavis Dockwiller, ASLA, a principal with Viridian Landscape Studio in Philadelphia, says that she has begun working with plant ecologists to ensure that the plant mixes for her projects are not only native (itself a novel concept not too long ago) but biologically diverse – an even more sustainable solution.

If using recycled-content products is desirable but fraught with hidden concerns, then what about salvage? Reusing existing materials seems, on its face, to be an environmentally sound and low-energy form of recycling. Some observers believe, however, that promoting the salvage of existing materials simply encourages more demolition, while others think that the catch-as-catch-can nature of salvage will never be reliable enough for this to become a major issue.

"I think a central concept in sustainability is to eliminate the concept of waste, and in this regard I think building salvage is a great thing," says Vottero. "However it is important to note that the condition that we should be developing is whole building salvage and deconstruction instead of whole building demolition. The current concept of 'building salvage' is really little more than looting."

If buildings were required to be disassembled instead of demolished, he says, it would achieve the dual goals of eliminating waste and preserving embodied energy. "We should salvage brick and masonry materials, rather than crushing them into aggregate," he says, "and salvage framing lumber rather than grinding it into mulch."

Setting the Standard
As sustainability matures as both a concept and a market driver, architects and other design professionals are likely to depend even more heavily on third-party rating standards to help sort through the abundance of green products. In addition to the aforementioned Energy Star system, other popular third-party standards include those developed by the Forest Stewardship Council, Green Seal, the Sustainable Forestry Initiative, and the Greenguard Environmental Institute, among others.

Architects are increasingly defining sustainability for themselves as well. One notable certification standard is the Cradle to Cradle system developed by sustainable architect William McDonough, based in Charlottesville, VA, and chemist Michael Braungart, which promotes green product development and corporate responsibility.

The Miami-based firm Duany Plater-Zyberk & Company (DPZ), for its part, has taken sustainable product specification even further by tying it to traditional neighborhood planning. Led by its Charlotte, NC, office, DPZ's new Light Imprint New Urbanism (LINU) system employs a matrix by which engineers and designers can determine the most sustainable environmental strategies and materials across different "transect zones," ranging from rural to urban. For instance, paving options on the edge of a developed neighborhood might include a plastic mesh product or crushed stone and shell, while the urban core might require asphalt paving blocks. Filtration options might similarly range from a natural swamp in an undeveloped area to a bioretention swale or a grassed cellular concrete product in town.

DPZ developed the system (now in pilot form) when the firm realized that the engineers they worked with were taking a heavy-handed approach to sustainability and incorporating "gizmo green" products that were expensive and in some cases unnecessary, says Thomas E. Low, AIA, LEED, DPZ's director of town planning. The LINU model, he says, combines the most profound and visionary thinking about sustainability with the New Urbanist approach to development – walkable neighborhoods, mixed uses – that its adherents say is intrinsically sustainable. "The average American household averages 13.7 separate car trips per day," Low says. "If you were to mitigate between one third and two thirds of those car trips, is there anything else that would come as close to importance in green design? Therefore the issue is how green your neighborhood is. If you have a green building and everyone is driving to it, you're only part of the way there. We don't want to do green sprawl."

Just like a game show, sustainability poses many questions for the design profession. The answers lie not just in the products themselves, but in the careful consideration of where they came from, how much energy they embody and what lies ahead for them long after we're gone. Although the options seem endless, this is a game we truly all can win.  

 

 

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