Faceted facade evokes regenerative prairie burns.For most projects, admits VernerJohnson's Jonathan Kharfen, architects steer clear of evoking a potentially destructive force like fire. But Museum at Prairiefire, the American Museum of Natural History (AMNH) outpost in Overland Park, Kansas, proved an exception to the rule. Because Prairiefire houses AMNH's traveling exhibits, its content is constantly changing, and thus provided little guidance in terms of an overarching design concept. Kharfen instead looked to the location. "What is the area about?" he asked. "For me the first thing that came to mind were the prairie burns. Coming from Boston, I'd never seen anything like it." Using dynamic materials including dichroic glass and iridescent stainless steel, VernorJohnson crafted a faceted high performance envelope that embodies the color, movement, and regenerative power of fire. Not long after landing on the fire metaphor, said Kharfen, "I knew of a couple of materials that would be perfect, because for me it's all about movement and light." He began researching dichroic glass, a composite glass that changes colors depending on the angle of view. The museum's sustainability goals—the project is targeting LEED Silver—dictated that the material would double as an insulating unit, the first such application in the United States. But that presented an additional challenge, as products with the dichroic properties embedded in the glass itself would break the budget. To lower costs, the architects collaborated with fabricator Goldray Industries to design an assembly incorporating dichroic film from 3M. The solution turned out to be an aesthetic boon as well as a cost-cutter, as the film itself carries a flame-like pattern. "It's subtly dimply, it's animated, it's beautiful," said Kharfen. Kharfen's team paired the dichroic glass with a second shape-shifting material, Light Interference Coated (LIC) stainless steel, ultimately applying panels in a variety of color and finish combinations. "With the stainless steel, I wanted to create [the appearance of] flame bursts and sparks," explained Kharfen. "I didn't want to apply it in a random way." Instead, the architects arranged the panels in a gradient, with blue (near the bottom) giving way to burgundies and reds and finally to golden yellow. For Kharfen, it was not enough that the materials themselves convey a sense of life and movement. "I wanted them to be dynamic shapes, dynamic in plan as well as in elevation," he said. His solution—a faceted curtain wall—upped the project's technical ante. To avoid cluttering up the lobby space with columns, Kharfen worked with structural engineers Structural Engineering Associates to design a custom support system of stainless steel tubes fronted by angled mullions, to which the curtain wall is attached as a veneer. To accommodate the 14 unique angles involved in the faceting, curtain wall manufacturer Kawneer developed a new adjustable mullion, a hinged plate with a 180-degree range of movement. Given the museum's ever-changing content, the architects treated the exhibit spaces as "black boxes," said Kharfen. "For the solid areas I wanted to evoke the overlapping, curved forms of the hills." The client, Fred Merrill of Merrill Companies, loved the stonework at VernorJohnson's Flint Hills Discovery Center in Manhattan, Kansas, which suggests striated rock formations. "He asked, 'Can't we just do that here?'" recalled Kharfen. "I said, 'No, we're going to do something different.' I wanted a gradient." To cut costs and simplify installation, the architects whittled a more complex scheme down to a mix of two different stones in each band, with the bands varying in width. Again, the referent is fire: the walls begin with a charcoal-colored architectural cast stone before moving through Kansas limestone in shades of red, brown, gold, and off-white. Together, the stone-clad exhibit halls and the lobby curtain wall complete the picture of a prairie burn. "I wanted the fire elements to engulf and connect the solid volumes," said Kharfen. "I did them as lines of fire, because, historically, that's how these fires were set." But while the burn metaphor extends to every level of detail, including the flicker-flame-inspired sloping at the tops of the doors and windows, for the project architect the museum design ends where it began: with the primary materials. Speaking again of the dichroic glass, he concluded, "I cannot think of a material that looks more like fire than this glass."
Posts tagged with "LEED":
Boston launches a sustainable housing initiative with net-zero energy townhomes.As anyone who has come into contact with Red Sox Nation knows, Bostonians tend not to believe in half measures. A case in point is the city's E+ Green Building Program, a joint initiative of the Office of Environment & Energy Services, the Department of Neighborhood Development, and the Boston Redevelopment Authority. Designed to demonstrate the feasibility of building net-zero energy, multi-unit housing in an urban context, the program made its built debut in 2013 with 226-232 Highland Street, a development consisting of four three-bedroom townhomes in Boston's Roxbury neighborhood. The building achieved substantial energy savings on a tight budget in part through a highly insulated facade constructed from conventional materials. "The envelope is key," explained Interface Studio Architects (ISA) principal Brian Phillips. "We design many super high performance projects and we believe strongly in the quality of the envelope as the starting point." ISA became involved in the project at the invitation of developer Urbanica, who had seen their 100K Houses, a high performance housing prototype designed to be constructed at less than $100 per square foot. One of three winners of the E+ Green Building Program's developer design competition, the Urbanica-ISA team crafted the townhomes with a dual awareness of the project's immediate surroundings and efficiency goals. "We're always interested in observing and measuring the context in order to create our design approach," said Phillips. "The materials and shapes of the Roxbury neighborhood inspired our design—as well as the requirements of creating a super high performance building." For instance, he describes the facade's most distinctive feature, a recessed vertical stack of windows, as "a riff on the prevailing bay window typology." The architects' material choices "were motivated by aesthetics, affordability, and recycled content," said Phillips. The primary facade material, prefinished fiber cement lap siding, is common to the neighborhood's existing residential fabric. Each attached house features an interlocking pattern of grey-blue and cedar-textured siding, for contrast, while the reverse bay windows are wrapped in dark grey metal panels. Double-stud walls, blown in insulation, and super tight doors and windows reduce thermal gain to a bare minimum. Thanks to its high performance envelope, energy-generating rooftop photovoltaic panels, and integrated user-feedback system, 226-232 Highland met the E+ Green Building Program's concrete goals, earning LEED Platinum for Homes certification and HERS Index scores between -11 and -15. Even during the unusually cold winter of 2013-2014, the Boston Redevelopment Authority reported, the project recorded energy positive days. But the townhomes also fulfilled the less tangible component of the city's mission, as a demonstration that sustainable housing can be built simply and for a reasonable price. "Green development is no longer just the big high-rises and large projects downtown," said Boston Redevelopment Authority deputy director Prataap Patrose at an event celebrating the building's LEED Platinum certification. "It's happening here. It's happening in our neighborhoods."
Brick and metal transform a tired office block into a residential building worthy of its site.Located on a slice of land adjacent to the Potomac River in Old Town Alexandria, Virginia, the 1984 Sheet Metal Workers Union National Pension Fund building failed to live up to the site's potential. "I've used this in a couple of lectures," said Shalom Baranes Associates principal Patrick Burkhart. "I show 'before' photos and ask the audience, 'What is this building?' The answers include: 'It looks like an urban jail.'" When the property came on the market, Maryland-based developer EYA seized the opportunity to transform the waterfront eyesore into a contemporary condominium complex. Clad in brick and metal paneling, with high performance glazing emphasizing views along the Potomac, the Oronoco balances a sleek urban aesthetic with sensitivity to Old Town's historic fabric. Because rowhouses dominate Old Town's residential real estate market, "we thought there was a pent-up demand for one-level living for empty nesters," said EYA senior vice president Brian AJ Jackson. The developers took a "less is more" approach to the conversion, opting for 60 large units over the 110 allowed by the zoning code. They kept the old office building's stepped profile, creating penthouses on multiple levels, but carved out the center of the structure to make way for a courtyard. "The courtyard really gives the project a heart and soul," said Burkhart. "It creates something that's not inward looking, but outward." The Sheet Metal Workers Union building was "originally designed with fairly innovative sustainable ideas, for an office building," said Burkhart—including the stepped terraces, on top of which were solar collectors. "But a lot of it didn't work well." One major deficit was the structure's reduced window openings. During renovation, Shalom Baranes Associates focused on maximizing daylighting and views without sacrificing thermal or acoustic performance, selecting a variety of high performance products from Peerless for the building's glazed areas. Given the Oronoco's location along the flight path to and from Reagan National Airport, "the acoustic glazing is amazing," observed Choptank Communications' Brent Burkhardt. "You hear very little from inside the building, yet you have a neat view of the planes." The building's brick cavity wall offers additional benefits in terms of energy efficiency. "It's our theme to blend in," said Burkhart. "We decided to work with the brick aesthetic" that prevails among Old Town's older residences. The architects broke the building into townhouse-scale bays, wrapping every other bay in metal panels from Alcoa/Reynobond. "It alternates between brick and metal as you go up the steps: brick, then metal and glass, then another brick element. That helps pull you up the height of the building," explained Burkhart. The LEED Silver Oronoco achieves the performance aspirations of its predecessor without neglecting the building's visual appeal—and without taking unnecessary risks. Obtaining LEED certification "is always a little more challenging for residential designs," said Burkhart. "Many of the points are developed simply through a careful selection of materials, instead of choosing more exotic measures."
Modular self-shading system delivers budget-friendly environmental performance.Tapped to design the facade for the HUB-1 office building at Karle Town Centre in Bangalore, India, New York–based Merge Studio faced a two-pronged challenge: crafting an efficient envelope that would beat the heat without breaking the developer's budget. Moreover, the architects (whose role later expanded to include landscape and public space design) aspired to lend the twelve-story tower, the first in the 3.6 million-square-foot SEZ development, an iconic appearance. "The idea was that we bring together the aesthetics of the facade and make it performative as well," explained Merge founder and advisor Varun Kohli. Despite financial constraints dictated by India's competitive development market, Merge delivered, designing a modular facade comprising metal and glass "waves" that cut solar gain while allowing light and air to penetrate the interior. Solar analysis helped dictate Merge's overall strategy for the building envelope. "In this climate, the maximum impact in terms of heat loads happens through direct radiation, as opposed to conductive heat transfers, which meant that the shading aspect was most important," said Kohli. To lower costs, the architects came up with the idea of a modular, self-shading system in which successive "waves," oriented vertically, shade adjacent glazing. They also streamlined construction through a combination of a minimal material palette and off-site prefabrication. Though Merge had to special-order 1.5-meter Alubond panels, "everything else was fairly simple," said Kohli. "We made sure that there's no glazing where the aluminum panels curve." Mumbai's SP Fab manufactured and installed the facade, splitting each "wave" into three prefabricated pieces that were then trucked to the site and hooked on. HUB-1's glazing was carefully plotted according to the solar studies, with windows decreasing in size on the tower's upper levels. The architects also reduced the window-to-wall ratio on the east- and west-facing sides of the building. They selected double-glazed windows with a low-e coating from St. Gobain India. "It's one of the few buildings using the most high performance glass available in the country," noted Kohli. "It was a careful selection of [performance] strategies." Ventilation is provided by operable vertical slot windows between the crest of each "wave" and the adjacent panel. "Studies showed that we would be able to grab more air through those because of turbulence as it moves around the surface," said Kohli. Some of Merge's initial hopes for improved environmental performance were quashed by the financial reality on the ground. "Obviously, we made a number of compromises along the way," said Kohli. "But I think we can still prove that we were able to save energy in the range of 15-16 percent due to the facade alone." The building as a whole, which will be complete this spring, is targeting LEED Gold certification. Kohli also noted the self-shading system's potential, given a different set of circumstances. "When we first started developing this, we had enough variables that we could really manipulate the facade in response to the environment; the curves could be larger or smaller, and other variables," said Kohli. "But given the fact that we're designing in a market that's very tough financially, we had to really dumb it down. There's quite a bit of [room to explore]."