LEED Platinum renovation reconnects the Health Services Building to the campus core.Early in their renovation of the Arizona State University Health Services Building, Lake|Flato Architects, working with orcutt | winslow, decided to scrap the university’s initial concept in favor of a plan that would reengage the campus’s historic pedestrian corridor, the Palm Walk. Instead of building an addition to the north side of the existing facility, which included a serviceable two-story building constructed in the 1950s and another structure Lake|Flato partner Andrew Herdeg described as "a rambling one-story rabbit warren of spaces," the architects elected to demolish the one-story wing and build a two-story addition in its place. "This initial idea that we need to look at the basic concept before we start the design, and think about it from the campus design perspective, changed everything," said Herdeg. It allowed the design team to reduce the program by about 12 percent and reduce the footprint by 20 percent, as well as to preserve 5,000 square feet of green space for programs and stormwater mitigation. But it also presented a challenge. The renovated building’s primary identity would be on the east facade of the building, where the desert sun had the potential to undo efficiencies gained elsewhere. Lake|Flato and orcutt | winslow responded with a building envelope that provides a strong visual connection to the Palm Walk while reducing solar gain to the absolute minimum. The architects wrapped the south and west sides of the addition, where the clinics are located, in a tight brick over rigid fiberglass insulation. "The brick picks up on some surrounding historic buildings, and is also a traditional material for the campus," said Herdeg. The designers articulated the east side of the building with a series of bays and adjacent pocket gardens. The bays are oriented to the south and southeast, rather than due east, with the glazing on their south facets. "Instead of thinking about engaging the campus in a frontal way, we always thought of approaching this building on the diagonal," explained Herdeg. "Thinking about how the pedestrian perceives it helped us strategize about solar assets and thermal loads." The unglazed portions of the bays are clad in a metal skin, behind which an inch and a half of rigid insulation serves to eliminate thermal bridging. The articulated facade is designed to self-shade as the sun rises. "We worked on a series of pretty rudimentary daylighting studies that allowed us to look at the spacing of the bays," said Herdeg. "We did this balancing act between creating little pocket gardens, and using the adjacent bays to self-shade the glazing on the bays next to them." The design team installed corrugated metal overhangs over the bay windows to provide additional protection from direct sunlight. A series of recycled wood pulp and plastic screens from Trex, installed over the bay windows and over some of the glazing on the south and west sides of the building, constitute a final layer of defense against the Phoenix sun. "The Trex louver system allowed the solar thermal to be picked up on the lattice rather than the building skin; it was another barrier to the thermal load," said Herdeg. "The lattice also supports vines that are going to grow up, so these pocket gardens get surrounded by lush vine-covered walls." Likewise, on the new building’s two other facades, "the thought was that each of the little patient rooms would not be looking out at parking, but at a green screen," he explained. Lake|Flato and orcutt | winslow’s LEED Platinum intervention, which included replacing all the single-pane windows in the 1950s building with low-E insulated glass, will surely save ASU substantial sums on its energy bills. More importantly—thanks to the designers’ decision to demolish the inefficient one-story wing—it weaves the Health Services Building back into the campus fabric. "Now the building really addresses the campus," said Herdeg. "Before it had this very disjointed identity. Now we’ve created a cohesive identity with a single entrance. It’s a much better solution."
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Sustainability and high design meet in Leddy Maytum Stacy Architects' affordable housing complex.Designing a sustainable building on a budget is tricky enough. But for the Merritt Crossing senior housing complex in Oakland, California, non-profit developer Satellite Affordable Housing Associates upped the ante, asking Leddy Maytum Stacy Architects to follow not one but two green-building ratings systems. "They wanted to push the envelope of what they typically do and decided to pursue not only the LEED rating, but also the GreenPoint system," said principal Richard Stacy. "So we actually did both, which is kind of crazy." Wrapped in a colorful cement-composite rain screen system punctuated by high performance windows, Merritt Crossing achieved LEED for Homes Mid-Rise Pilot Program Platinum and earned 206 points on the Build-It-Green GreenPoint scale. The building was also the first Energy Star Rated multi-family residence in California, and was awarded 104 points by Bay-Friendly Landscaping. Merritt Crossing’s 70 apartments serve low-income seniors with incomes between 30 and 50 percent of the area median. More than half of the units are reserved for residents at risk of homelessness or living with HIV/AIDS. Stacy explains that in the context of affordable housing, sustainability means two things. The first is quality of life for the residents, "the sorts of things that have a direct benefit to the people living there," such as natural daylighting and indoor air quality. The second is energy efficiency. "Both non-profits and [their] residents have limited financial capabilities," said Stacy. "The one time they have funding for that kind of thing is when they’re building a building. So we focused a lot on the building envelope in terms of energy efficiency. At the same time, we wanted to have ample daylight and controlled ventilation.” Finding themselves with unused contingency funds during construction Leddy Maytum Stacy Architects upgraded the exterior skin to a rain screen system of SWISSPEARL cement composite. "We worked pretty closely with the SWISSPEARL company," said Stacy, who noted that Merritt Crossing may be the first building in the United States to use the system. Though the panels are installed like lap siding they offer "the benefits of a rain screen in terms of cooling and waterproofing issues," he explained. To accommodate the thicker skin, window manufacturer Torrance Aluminum designed custom trim pieces, which "had the added benefit of giving us the appearance of deeply recessed windows," said Stacy. Insulation was a special concern for the architects, both because Merritt Crossing was built using metal frame construction, and to minimize air infiltration in keeping with the green ratings systems. The building’s exterior walls are wrapped in 1-inch-thick high performance polyiso insulation from Dow Corning with a Grace Perm-A-Barrier VPS vapor permeable membrane. "As a result we ended up with a very, very tight building from an air insulation standpoint, which means you have to pay more attention to air ventilation," said Stacy. To compensate, Leddy Maytum Stacy Architects’ mechanical engineers designed a special air filtration system for the building’s roof, complete with built-in HEPA filters. The building’s southwest facade faces a freeway, presenting potential noise and privacy issues in addition to exposure to the western sun. "We did a highly layered facade on that [side] where the actual exterior wall is back three to four feet from another screen wall," said Stacy. The outer wall "is a combination of typical wall assembly as well as GreenScreen panels that form a webbing of open areas and solid areas that help with sunshading as well as acoustical [dampening] and privacy." Greenery in balcony planters will eventually grow up and over the screens. On the ground floor, the garage is also enclosed in GreenScreen trellising, to enhance pedestrians’ view without sacrificing ventilation. Leddy Maytum Stacy Architects’ Merritt Crossing proves that affordable housing does not have to look institutional. The facade’s vibrant colors—green on the northeast elevation, red on the southwest—and playful punched texture pay homage to the neighborhood’s patchwork of architectural styles and building uses. The first major building in the planned redevelopment of the area around the Lake Merritt BART regional transit station, Merritt Crossing sets the bar high for future developments.