Though sustainability remains a primary goal for many AEC industry professionals, its definition is increasingly up for debate. Tried-and-true energy efficiency standards such as LEED and Energy Star are facing competition from other rubrics, including net zero. "LEED was the sustainability measure," said CO Architects' Alex Korter. "It's good, but people looked at it more as a certification. With net zero, you're setting hard performance goals." With his colleague Kevin Kavanagh, Korter will lead a panel on "Net Zero and the Future Facade" at Facades+ LA next week. Korter, Kavanagh, and the panelists—who include ARUP's Russell Fortmeyer, Atelier 10's Emilie Hagen, and Stephane Hoffman from Morrison Hershfield—will dig in to the what and why of net zero, and ask how facade designers and builders can push the envelope on environmental performance. Both Korter and Kavanagh see room for improvement in terms of how facade designers and fabricators address sustainability. "Something that we've talked about—and something that will get us in a bit of trouble—is that we don't think the envelope world has done well in terms of upping performance," said Korter. Part of the problem is the focus on checking boxes for energy certifications, rather than setting concrete goals. Even in the world of net zero, said Kavanagh, "the facade is often looked at as an insulating layer, and is relegated to a high-performance insulating component. Our argument is that if you want to maximize net zero, architects and developers really need to rethink their approach to building. Why are facades trying to get as thin as possible? It makes sense for an Apple Store, but for other buildings, why not a two-foot-thick facade with [integrated mechanicals]?" The logical extension of the critique posed by Korter and Kavanagh is, as Kavanagh put it, "Is it possible for a facade to make a building net zero?" But to get there, the two say, designers and fabricators will need a push as well as a pull. "The way this is really going to happen is that the code tells you to, or the building owner—the person who pays the bill—starts to make it their number one priority," said Korter. "Those are the two ways. We've been dancing in this nebulous time: We could do it, but do we really have to?" Hear more from facades experts on net zero and other pressing issues next week at Facades+ LA. To learn more and register, visit the conference website.
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The Vancouver-based New Buildings Institute (NBI) tracks energy efficient built work, and their 2014 update, “Getting to Zero”, provides a snapshot of the emerging U.S. market for net-zero buildings—those are structures that use no more energy than they can gather on site. In the United States, California leads in the number of low and zero energy projects with 58, followed by Oregon (18), Colorado (17), Washington (16), Virginia (12), Massachusetts (11), Florida (10), Pennsylvania (10), Illinois (8), North Carolina (8), and New York (8). NBI also compiled a database of all their buildings. They say architects and developers interested in pursuing net-zero design could find inspiration there, searching according to their local climate and/or building characteristics. The database includes energy-efficient and high-performance buildings that are not net-zero, as well. Though the trend has succeeded in garnering attention and excitement among many designers, true net-zero buildings remain elusive in the built environment. So far NBI has only certified 37 buildings as net-zero. That ranking is based on performance—each building underwent a review of at least 12 months of measured energy use data. If piece-meal projects aren't yet adding up to a groundswell of net-zero design, NBI is also pushing systemic change—rigorous energy efficiency standards recently adopted in Illinois took cues from the group's Core Performance Guide.
Net zero energy, LEED Platinum project raises the bar on eco-friendly office design.For its new headquarters in Los Altos, California, the David and Lucile Packard Foundation put its building budget where its mouth is. The philanthropic organization, whose four program areas include conservation and science, asked San Francisco-based EHDD to design a net zero energy, LEED Platinum building that would serve as a model of cutting-edge green building techniques. “They wanted to achieve net zero in a way that was replicable, and that showed the path forward for others to follow,” said project manager Brad Jacobson. “It was not just a one-off thing, not just a showcase.” The building’s facade was fundamental to its success as an example of sustainable design. “We were surprised at how significant the envelope is, even in the most benign climate,” said Jacobson. “Pushing the envelope to really high performance made significant energy and comfort impacts, and could be justified even on a first-cost basis.” EHDD began by considering the building’s siting. Because the street grid in Los Altos is angled 40 degrees to the south, orienting to the street would result in a long southwest elevation. The architects asked daylighting consultants Loisos + Ubbelohde what penalty this would entail. “They said you have to keep all solar gain out of the southwest facade; if you do that, the energy penalty will be in the realm of less than five percent,” recalled Jacobson. “But you really have to do an excellent job on sunshading. That was our mission.” EHDD designed deep overhangs over much of the facade’s southwest face, and added balconies and shade trees for additional protection. Where the glazing remained exposed, they installed external movable blinds from Nysan that operate on an astronomic time clock. “The blinds worked really well,” said Jacobson. “We were surprised how easy they were to commission and get working, and how relatively robust they are.” Thermal bridging was another area of concern for the architects. EHDD worked with Atelier Ten on thermal modeling of the wall, and discovered that any metal stud wall would sacrifice performance. They opted instead for wood stud construction, and switched to 24 on center framing to reduce thermal bridging through the framing structure. For insulation, the architects added one-inch external mineral wallboard from Roxul. On advice from structural engineers Tipping Mar, they installed FRP plates to separate external elements like balconies from the main structure. Because of the building’s location, EHDD did not initially consider triple glazing for the Packard Foundation offices. “We wrote it off at first,” said Jacobson. “We thought, that can’t be cost effective in this climate.” But Integral Group’s energy analysis convinced the design team otherwise. The improvement in comfort allowed by triple element windows from Serious Materials (now Alpen HPP) was such that the architects were able to eliminate a planned perimeter heating system, resulting in an estimated savings of twice the cost of the glazing upgrade. “It’s a really good envelope,” said Jacobson. “We did heat sensor testing of the building, and you can really see that it’s working as it’s supposed to. You don’t see the studs, and the windows are not leaking a lot of heat, so that’s been a real success.” The architects clad the building in local and sustainable materials, including FSC-certified western red cedar, stone sourced from within a 500-mile radius, and architectural copper. “Architectural copper is a really interesting material,” observed Jacobson. “It’s actually about 80-90 percent recycled because it’s valued. It doesn’t need refinishing and it patinas nicely. For a building being built to last 100 years, it has a good shot at never needing to be refinished or replaced.” Jacobson summarizes his firm’s approach to the design of the Packard Foundation headquarters as “Passive House light.” “At the same time we were doing a Passive House for a climate science researcher we’d worked with in the past,” he said. “We were working on both and learning from each. It’s a different type of building, but a lot of the same principles apply: good air sealing, eliminating thermal bridging, and pushing the envelope further than you think makes sense.”
The newly opened Bullitt Center in Seattle has stridden beyond the checklists of the LEED rating system to bring "real green” architecture into the public’s eye. As the self-proclaimed “greenest commercial building in the world,” the Bullitt Center seeks to meet the exacting goals of the Living Building Challenge, a more rigorous certification alternative to LEED. Located in Seattle’s Capital Hill district, which is in the process of a metamorphosis into the city's "Eco-District," the six-story building aims to serve as a new standard for what can be accomplished when architects and developers put ecological design at the forefront of their priorities. Designed by Seattle-based Miller Hull Partnership, the carbon-neutral building incorporates a bunch of green features to address nearly all of its energy and waste needs, while promoting sustainable behaviors through its design and program. The $30 million building is toped with a solar array and rainwater catchment system that provide for all of its electrical and water needs. All wastewater is stored and treated onsite and gray water will be used to irrigate the building’s planted areas. The site encourages pedestrian, bike, and public transit based lifestyles, while the internal layout promotes a healthy routine by way of a large, welcoming, well-lit stairway. To achieve net-zero status, the architects raised ceilings and installed large operable windows so that artificial lighting is barely necessary and all employees can be assured ample daylight and fresh air in the workplace. Geothermal heat pumps reduce the energy demand of the heating and air-conditioning system. Finally, all “Red List” building materials—materials that the government has determined to be harmful to animals, including humans—have been banned from the site. The Bullitt Center is set to officially open its doors for Earth Day. With its expected lifespan of 250 years—compared to 40 years for typical commercial buildings—the building just may stand as a premiere model of sustainability for generations to come.
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A motorized green wall that reads the weather and adjusts automaticallyTwo years ago six students and three faculty from Virginia Tech's School of Architecture + Design spent three weeks at SOM's Chicago office applying industrial fabrication solutions to the problem of high density housing for Southworks, a housing development that's currently being planned for a large vacant section south of the city. The result was LumenHAUS, an aggressively energy efficient home that won the international Solar Decathlon Competition that June for sustainable solutions to high density construction. LumenHAUS is not only net zero, it actually creates more energy than it uses by implementing, among other innovations, a modular system that autonomously responds to external weather information and internal environmental conditions to optimize energy use. This Fall Virginia Tech's Center for Design Research will begin construction on a full scale prototype of six housing modules, including a working prototype of Hanging Garden, a dynamic plant wall that reads the weather and responds by sliding along the walls and windows to either block or allow sunlight into the living unit. Hanging Garden combines automated shading control with the emerging demand for urban garden space. Each unit is composed of a series of planters and and can be configured into one of three scenarios: (1) fully nested against the side walls of the south facing projecting balcony, (2) partially deployed to protect the balcony from east or west light or wind or (3) fully deployed and aligned with the outer face of the balcony (rotated 90 degrees). Each unit can automatically adjust to accommodate changing weather patterns, plant type and user demands by means of an actuated track system provided by Hafele. Two ceiling mounted tracks run parallel to each other until the garden reaches the outer balcony. At this point the slave trolley follows the radial track and sends the garden plane horizontally along the outer edge of the balcony. "The plant wall system is integrated into our ‘responsive architecture’ smart home building control system, which was developed for the LumenHAUS," said Virginia Tech faculty member Joe Wheeler. "With real time data from both the house-mounted weather station and from interior environment sensors, the computer can detect when shading is needed or when direct solar gain is needed. For example, on a summer day when the system is in cooling mode, exterior temperatures are high and the daylight sensors detect full sun, plant walls are deployed into the full shade position along electronically controlled motorized tracks." The Hanging Garden system can be built into a larger outdoor garden patio configuration that allots two outdoor spaces on either end of the main living module. During warmer months the patio can be opened up completely, providing cross ventilation. In colder months they can be closed to act like greenhouses and serve as insulating buffers to the indoor space, becoming passive mechanisms of energy efficiency. Even those whose thumbs are anything but green can easily keep their Hanging Garden growing year-round, thanks to the self-watering system - also a great feature for when you're out of town. "When the plant walls are in their "home" position, a reservoir is refilled by a ceiling mounted valve," Wheeler explained. "The reservoir directs water to each individual pot on the wall and a floor drain in the balcony collects any overflow." The final product will have a CNC cut steel frame and slip cast ceramic pots, but the prototypes for the six modular units will be made from MDF, an odd choice for such an environmentally progressive project, though perhaps the longterm benefits of Hanging Garden, and of the Southworks complex in general will ultimately outweigh a few preliminary MDF models?
The new Electrical and Computer Engineering (ECE) building at the University of Illinois at Urbana-Champaign uses the latest in sustainable technology and building practices in hopes of reaching not only LEED Platinum, but even zero net energy usuage. Designed by SmithGroup, the 230,000 square foot building is also meant to serve as a prototype for sustainable building across the campus. The ECE department is working toward a net zero building that will supply one hundred percent of its energy demands by incorporating renewable energy systems. The architects and engineers from KJWW have integrated a range of system, including an array of photovoltaic cells panels, displacement and demand control ventilation, heat recovery chillers with net metering, and a chilled beam system for cooling and heating the classroom tower. The building also features solar shading and a multi-hued terra cotta rainscreen over an R30 building envelope. Construction is expected to begin at the end of this year, with an estimated completion date of fall 2014.