Posts tagged with "Passive House":
Today at Facades+ New York, The Architect's Newspaper's conference series on innovative building envelopes, AEC professionals gathered for a day of talks on the challenges and opportunities presented by the design and construction of high-performance facades.
To kick off the afternoon session, Blake Middleton, partner at Handel Architects and Lois Arena, senior mechanical engineer at SWA convened to talk about “The House” at Cornell Tech. The 26-story, 350-unit building, on Roosevelt Island on the East River, is the largest Passive House–certified structure in the world. AN editor-in-chief William Menking was on hand to moderate the post-talk Q+A.
Passive House certification, Arena explained, is the most rigorous building standard in the world. Why? The certification is based on performance—and the performance levels that Passive House demands are five to ten times higher than current building codes require. So, to meet the exacting standards, Arena and Blake revealed just how they rose to that challenge with their project at Cornell Tech.
There are six key factors, Arena said, to achieving the certification: siting, compact shape, the proper enclosure, a low energy HVAC system, energy efficient appliances and lighting, and, crucially, user-friendliness.
The Cornell Tech building is sited due south to maximize solar gains. Middleton added that minimizing the facade’s exposed surface area was key to the certification: the designers used a “wrap” metaphor for what the facade might be, a form that's connected to the geology of the island. With a facade that’s 23 percent glass, “the design goal was to break down that scale and solidity with banding,” he said.
Functionally, the team used a prefabricated panelized wall frame for the facade, both for quality control and to achieve desired R-values of 19-40, depending on the wall’s thickness at various points.
To really double down on efficient energy use, The House has a feedback system to encourage occupant participation whereby residents can see how much energy they are using. The system, as a result, promotes friendly competition between floors to meet or beat projected energy use. Meanwhile, a centralized mechanical ventilation system helps maintain optimal airflow, but each room—per Passive House standards—comes equipped with fully operational windows to encourage natural ventilation.
Building on the success of the Cornell Tech project, the team’s next projects include a 700-unit Passive House–certified affordable housing development in East Harlem. To find out more about The House, check out another Q+A AN did with Blake earlier this week as well as more previous coverage here.
"To make sure that all sustainability criteria are considered, we coordinate an integrated general planning team with clear communication structures and a customized working process from the first conception until the phase of use." - kadawittfeldarchitekturKadawittfeldarchitektur has built a modern energy efficiency center on the campus of Hochschule Niederrhein in Mönchengladbach, a city in North Rhine-Westphalia, Germany. The zero emission building is constructed to Passive House standards which require thermal bridge free design, superior windows, ventilation with heat recovery, quality insulation and airtight construction. The driving idea behind the project was to unite the science and energy industry with the university in a collaborative effort to share innovative energy technologies with the public. The building accommodates an energy center for NEW, an energy and water utility company, along with an academic library, a startup center for new business ventures, and an energy laboratory for students. The building is designed to be an object in the landscape – a “solitaire” according to Mathias Garanin, Project Manager for kadawittfeldarchitektur. “Due to its conception as a solitaire, it is a building without a rear elevation, a building that faces public space in all directions.” Garanin and the kadawittfeldarchitektur project team say the building volume was based on setback distances from neighboring buildings, creating a compact, five-sided volume clad with oppositely inclined blue tinted glass and photovoltaic panels coordinated with the orientation and incidence of solar radiation. “The NEW-Blauhaus building is kept at a distance in order to establish new relationships.” Benefits to the volumetric shape of the building include a favorable volume-to-surface ratio for energy efficiency and a relatively short interior travel distances to maximize collaboration. While the architects have produced a formally engaging homogeneous skin, loaded with performative features acknowledging insulation requirements, acoustics, durability, and user comfort, perhaps the most important role of the building is to clearly communicate a high performance energy agenda. This is achieved in two ways: in the facade, which is clad with photovoltaic panels, and at the base of the building, where an energy center doubles as a showroom visible to onlookers from the exterior. Here, visitors can engage in displays showcasing sustainable energy, along with a specialized highly efficient reversible heat pump system involving an ice storage tank and chiller plant. kadawittfeldarchitektur says the facade is the building’s most exclusive means of expression. “As a significant part of the advanced energy concept, it communicates the approach to conserving resources to the outside and determines the identity of the architecture and its users in the urban environment.” A 4-foot structural grid establishes stacks of window and photovoltaic units that are variably rotated to most effective solar angles. Soundproofing panes located in front of the widow units work to compositionally complete the building envelopes patterned ornamentation. The window units are operable, providing individualized user comfort as required. The north facade receives enameled glass in place of the photovoltaic panels along the north facade were omitted from the design due to performative issues, and replaced with an enameled glass. The elegance of the envelope system inspired an interior design scheme of clarity and communication through “color blocking.” Based on the activity of the building as an energy generation system from dusk to dawn, the coloration of interior spaces combines hues of a defined color spectrum found in sunset and sunrise conditions.
Architects deliver a North American first with Warren Woods Ecology Field Station.When Belfast, Maine–based architecture firm GO Logic presented the University of Chicago's Department of Ecology and Evolution with three schematic designs for the new Warren Woods Ecology Field Station, the academics decided to go for broke. Despite being new to Passive House building, the university was attracted to the sustainability standard given the laboratory's remote location in Berrien County, Michigan. "We presented them with three design options: one more compact, one more aggressive formally," recalled project architect Timothy Lock. The third option had an even more complicated form, one that would make Passive House certification difficult. "They said: 'We want the third one—and we want you to get it certified,'" said Lock. "We had our work cut out for us." Thanks in no small part to an envelope comprising a cedar rain screen, fully integrated insulation system, and high performance glazing, GO Logic succeeded in meeting the aesthetic and environmental goals set down by the university, with the result that the Warren Woods facility is the first Passive House–certified laboratory in North America. Warren Woods' envelope begins at ground level, with a shallow foundation utilizing GO Logic's patented L-shaped EPS insulation around the edges, and a continuous air-seal layer between the foam and the slab. "The system allows us to pour consistent slab-on-grade without any thermal bridging," explained Lock. The sealing layer connects into the wood stud wall backed by graphite-impregnated Neopor insulation. The architects chose the insulation for its high R-value, knowing that they would need to compensate for the relatively large amount of surface area dedicated to the exterior wall. Pro clima one-way breathable building paper allows the building to expel moisture. GO Logic installed a rain screen of Eastern White Cedar vertical gap siding sourced from the Upper Peninsula "because of the aesthetic goals of the client," said Lock. "They desired a contemporary aesthetic but also [the look of] a Midwestern barn." The architects planned the interior space and allotted glazing judiciously, locating the laboratory on the north side of the building. Its position, under the cantilever over the entry, maximally reduces solar gain—an important consideration given the heat generated by the equipment inside. The classroom space, on the other hand, is positioned on the building's south side, punctuated by a long strip of Kneer-Südfenster glazing. "We are highly critical of windows that are available domestically," said Lock. "The big drawback with North American windows is that the tradeoff for a higher R-value is significantly reduced solar heat gain." Instead, the firm imports Kneer-Süd's products directly from Germany. "In Northern Europe they know how to get all the heat from the sun that they can," he observed. "We also love the way they look." The windows and doors are fully integrated into the air-seal layer using one-way breathable tapes from SIGA, imported (like the pro clima paper) through 475 High Performance Building Supply in Brooklyn. A custom-fabricated stainless steel accordion screen shields the classroom-side glazing from both intruders and the sun. "It's good for security—the university likes that," said Lock. "But the screen was also big for us to control the amount of heat that enters during the summer months and shoulder seasons." The idea, he explained, is that when classes are in session and the weather is nice, the occupants can throw open the doors. When only the laboratory is in operation, the closed screen will cut back on heat gain. In addition, the steel mesh "became something that was also a really exciting design feature," said Lock. "It had a great effect—not just cooling the space, but also softening the natural light."
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.”