A custom concrete curtain wall complements a Singapore university building's unique form.The new Learning Hub at Nanyang Technological University (NTU) in Singapore looks nothing like a typical campus building. School administrators conceived of the facility as the embodiment of a pedagogical sea change, and commissioned London-based Heatherwick Studio to design an iconic structure emphasizing small-group learning and cross-disciplinary interaction. Eschewing perpendicular classrooms and isolated corridors, the architects developed a unique plan in which rounded meeting rooms are arrayed around a central atrium. The Learning Hub's textured concrete facade, punctuated by zig-zags of glazing and pockets of greenery, translates the interior program to the building's exterior, and announces the arrival at NTU of a new way of teaching and learning. The Learning Hub's plan, said project leader Ole Smith, "is basically the whole story of the design." The first challenge was to accommodate a radical departure in the university's mode of instruction. In lieu of traditional master classes, students meet in groups of six with a professor as facilitator. NTU asked Heatherwick Studio to eliminate corners where possible; once the architects observed that the classes would meet at round tables, the next step was to consider rounding the classrooms themselves. Knowing that the windows in the classrooms would need to be small in order to reduce thermal gain, they looked for another way for students to connect with one another and decided upon a central courtyard. "That was part of the brief as well, to enable the students to mix," said Smith. "It's the only building on the campus of 33,000 where they all come together. Art students might have class next to math or engineering students; the hope is that they'll meet up and inspire each other, or develop a business plan together." Singapore's stringent environmental standards necessitated the use of concrete on the building's facade as well as its structure. "That scared us a little," recalled Smith. "In northern Europe we see a lot of Brutalist buildings, and that's not the direction we wanted to go in. We started looking at how we could use the material in a different way." With local concrete contractor LWC, the architects played with pigment, using different colors to signal structure and ornament. In terms of form, they sought a balance between uniqueness and standardization. Heatherwick Studio's 3D modeling specialists came up with a set of 10 curvatures that, distributed across a total of 1,050 facade panels, could be recombined to deliver a unique shape to each classroom—thus streamlining fabrication without introducing obvious repetition. To further camouflage the facade's standardized elements, and to avoid swerving into Brutalist territory, the architects introduced a texture of horizontal bands, spaced, per local code requirements, to be pigeon-proof. In the end, explained Smith, "the panels are all unique because of the system we developed to treat the facade pattern." The system involved applying stripes of glue-like retardant onto the formwork, pouring the concrete, allowing it to set 24 hours, then hosing it down to remove the still-wet material. "We didn't add anything to the facade; we subtracted it," said Smith. To minimize solar gain, Heatherwick Studio introduced narrow bands of glazing around the perimeter of each classroom. Having rejected curved glass as too costly, but wishing to avoid a faceted appearance, the architects arranged the flat panes in a zig-zag pattern. A slight floor-by-floor cantilever further cuts the heat, turning each story into a natural sunshade for those below it. Meanwhile, induction units positioned under the windows passively ventilate the classrooms. Rounded bronze-mesh balconies situated between each classroom wing draw air into and through the courtyard, producing a cross breeze no matter the direction of the wind. The final pin in the Learning Hub's sustainability cap (the building achieved the highest sustainability rating awarded by the government of Singapore) is the hydroponic greenery distributed across the balconies and rooftop garden. For Smith, the ongoing collaboration with concrete fabricator LWC was a crucial element of the Learning Hub's success. The contractor's ingenuity and willingness to work with the architects provided the level of distinction required by the NTU brief. "We spent a lot of time with the consultants working on colors and texture," said Smith. "The concrete has a handmade feel; we're very happy with that. In Europe you pick your facade from a catalogue, but in this situation we were able to design it from scratch."
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Renovation transforms decommissioned McKim Mead & White building into campus event space.When Amherst College decided to convert a former steam plant into a student event space, the choice likely struck some observers as odd. Designed in 1925 by McKim, Mead & White, the coal-burning plant was decommissioned in the 1960s; since the 1980s, it had been used as a makeshift garage for ground equipment. The facade of the neglected building needed to be opened up to reveal its potential while respecting its good bones. "It wasn't in great shape, but it wasn't in terrible shape," said Bruner/Cott's Dana Kelly. "Impressively enough, the school recognized that it had qualities that could be harnessed for a new student space." The brick building's industrial aesthetic was a particular draw, said Kelly, whose firm has spearheaded renovations at the nearby MASS MoCA (itself a former industrial complex) since the museum opened in 1999. For Amherst College, Bruner/Cott took a similar approach, balancing preservation and alteration to support the new program without disrupting the historic building's essential character. By the time Bruner/Cott began work on the Powerhouse, the original brick envelope had already seen a lot of change. Earlier renovators had filled windows with glass block, rebuilt a blind arch in mismatching brick, and cut a large garage door into the south facade. "Since the building had been altered so much, we chose to continue the dialogue by restoring or reconstructing some exterior elements, and sensitively altering others to match the new use and open the building up to campus," said Bruner/Cott's Jason Forney and Aoife Morris. On the side of the building facing the campus road, the architects inserted a new steel and glass entrance into a blind brick arch. On the south facade, to connect the interior to the new outdoor terrace, they inserted historic replica windows and french doors in place of the glass block, and swapped out the roll-up garage door for a bi-fold glass door. On the north side, which faces the parking lot, Bruner/Cott retained the existing glass block. "The observer still reads the McKim, Mead & White design, but with the changes the building has evolved to be an extroverted part of campus instead of being an introverted coal-burning steam plant," said Forney and Morris. Environmental performance was a priority for the architects, who will monitor the building's energy consumption during occupancy. They talked Amherst College into opting for operable windows over mechanical cooling. For heat, they chose a hydronic radiant floor and an overhead infrared heater that runs on gas. "These systems work to heat the bodies of occupants, instead of heating the large volume of air in the space," explained Forney and Morris. An insulated chamber designed by Bruner/Cott captures waste heat from the new steam plant below the building and releases it into the event space during the winter. The architects chose not to insulate the interior walls "since their character was an important design element for the event space," said Forney and Morris. To compensate, they installed a new slate roof, heavily insulated with spray-on cellulose. The new roof, noted Forney and Morris, mixes two colors of stone "to achieve the mottled effect of the existing roof, which was beautiful but had outlived its lifespan." To avoid interrupting the Powerhouse's open plan, Bruner/Cott situated the restrooms in an understated addition constructed from board-formed concrete. "We find that additions like this are often necessary to support existing buildings without undermining their spatial qualities," observed Forney and Morris. To foreground the steam plant itself, "we chose to make the addition appear like a garden wall—a 'non-building,'" they said. "It is simply two offset concrete walls that conceal the door to the terrace." The contractor built the formwork from rough-hewn lumber to achieve a patinated look, and tinted the concrete to match the existing water table banding. The addition's gutters are designed to pour water down the face of the wall and hasten the appearance of age. Like Bruner/Cott's sensitive renovation, the steam plant's new moniker—the Powerhouse—effectively gestures at both the history of the building and its new incarnation as a campus activities hub. "Amherst College chose the name both to remind students of the building's industrial past, and to recognize its place in 21st-century student life," said Forney and Morris. Once responsible for producing heat, today the structure generates something less material, but equally important: student engagement.
As an engineer, Thorsten Helbig, co-founder of Knippers Helbig Advanced Engineering, has a unique perspective on facade design. "We conceptualize a facade as an integral part of a whole, as part of a larger system," he explained. Helbig, who will deliver the morning keynote address at next month's Facades+ NYC conference, identified two focal points. The first is the relationship of the building envelope to structure. The second is performance: "What can the facade offer back to the building?" Helbig asked Helbig queries all of his facade design choices. "Can we use the facade to capture energy for the building? What are the operation modes—is there a potential the facade could be flexible or adaptive to actively support the building functions?" In both cases, Knippers Helbig is invested in moving beyond yesterday's solutions. "Our engineering approach is fundamentally driven by our interest in innovation," said Helbig. Two areas in which Knippers Helbig is leading the innovation charge are design technology and materials. The firm began developing tessellation tools for grid shells about two decades ago, well before similar software was commercially available. In the years since, the engineers have refined their in-house technology into a multi-criteria optimization tool, which proved critical to the Shenzhen airport project. "Our work on the Shenzhen airport profoundly shaped our approach to design technology—as it relates to our basic understanding of the design process (or you might say process design)—and as it relates to a potential paradigm shift in project organization as a whole: away from the traditional hierarchical-linear design process toward a design of the process in which all design parameters are simultaneously considered," explained Helbig. As for materials, the firm is known for its facility with both conventional and "new" systems. Knippers Helbig capitalized on the flexible strength of glass fibre reinforced polymers (GFRP) first for an operable facade in a typhoon zone for South Korea's Expo 2012 pavilion, then for a proposed shading concept for Renzo Piano's Academy Museum of Motion Pictures in Los Angeles. "However," added Helbig, "even more traditional building materials such as timber can be re-interpreted through an application of the latest design and fabrication technologies." Two cases in point are a double curved multi-layer grid shell in Cologne and a parametrically developed timber grid shading screen for a Dubai high-rise. Knippers Helbig is also known for its sensitivity to environmental performance. Helbig points out that 75 percent of New York City's greenhouse gas emissions can be attributed to the building sector. "As long as we are not able to generate the required energy emission-free and based fully on renewable resources, the reduction of the operational energy will remain a key factor in designing sustainable buildings," he said. Embedded energy is also a concern, leading the engineers to explore materials that are based on renewable resources and/or compostable at end of life. Knippers Helbig recently collaborated on the EpiCenter Expansion for Artists for Humanity (with Behnisch Architekten and Transsolar), poised to become Boston's first LEED Platinum building and the first Energy Plus house in New England. "The facade system will be developed to have the capacity to supply energy back to the building, ultimately producing a building system that generates more energy than it consumes," Helbig explained. To hear more from Helbig and other movers and shakers in the world of facade design and construction, register today for Facades+ NYC. Visit the conference website for more information and a full schedule.
According to Francisco Gonzalez-Pulido, president of Chicago-based JAHN, contemporary facade design neglects one of the building envelope’s foremost responsibilities: storytelling. “There is a focus now on using the building massing to convey the key message,” he said. “However, I think it’s through the facade that we can bring a more compelling narrative about how the building functions.” As an example, Gonzalez-Pulido pointed to Mies van der Rohe’s One IBM Plaza, which he can see from his office. “When you look at the mechanical floors, they’re treated differently,” he said. “In the lobby, the glass is different. This is actually the responsibility of the facade—it’s more than a piece of glass and metal to cover the building.” Gonzalez-Pulido, who will deliver the afternoon keynote at facades+ Chicago later this month, framed the problem in terms of lightness. “Lightness is not only a physical property but a metaphysical property,” he said. “There’s been a tendency of loading skins with unnecessary elements for the sake of aesthetics. The facade is regulating so many important things that we have to be more conscious of it. If we are, the impact of buildings on the urban environment will be much more positive than it has been.” Architects should take their cue from the automobile and aircraft industries, he said, and discard homogeneity in favor of innovative materials and assemblies. The tendency toward standardization, Gonzalez-Pulido said, does not just have aesthetic consequences. It also sacrifices environmental performance. “It bothers me that buildings are so passive when the environment is changing constantly,” he said. “By facades being so mundane, as they are in a lot of buildings right now, we’re relying more on internal systems as opposed to the skin itself to really improve performance.” In the best-case scenario, the building envelope should facilitate “invisible acclimatization,” explained Gonzalez-Pulido, “creating ideal conditions of comfort and energy consumption without you being an active regulator or manipulator.” One key to correcting the imbalance between form and function, Gonzalez-Pulido argued, is convincing clients that high-performance facades are worth the initial cost. “That’s part of the reason why we’re creating this very boring look to buildings, because clients are so aware of what it takes to make a building inexpensive,” he said. “They’re pushing architects to the cookie cutter. This is dangerous—we’re not inventing things, we’re trying with aesthetics to make a difference.” Luckily, some clients can be talked out of a preference for glass boxes. This is what happened at the Veer Towers in Las Vegas (2010), where JAHN convinced an initially skeptical MGM that external shades were essential in a desert environment. “This is a remarkable story of how we were able to turn around the destiny of a building in its context, through collaborative effort, integrated design, and a committed client,” Gonzalez-Pulido said. Ultimately, it is up to architects to realize the building envelope’s full potential, Gonzalez-Pulido said. “Only if we push our boundaries, remove our preconceptions, and respond to the different context where we’re actually influencing through our design will we be able to make real progress,” he said. “It’s not just a technical question, but a moral question.”
Today's facade designers cannot afford to ignore the question of sustainability, and in particular energy efficiency. James O'Callaghan (Eckersley O'Callaghan), William Logan (Israel Berger & Associates), and Will Laufs (LaufsED) sat down with our partners at Enclos during April's facades+ NYC conference to talk about the push and pull between aesthetics and environmental performance in building envelopes. Top AEC professionals will continue the conversation at facades+ Chicago on July 24–25. For more information or to register, visit the conference website. Early Bird registration ends June 29.