Is wood dangerous? It’s one of the oldest, most sustainable building materials (if harvested correctly) and recent advances in cross-laminated timber (CLT) have made it possible to build taller, multifamily timber buildings, but local building codes are just beginning to catch up. Sure, any Girl Scout knows that you can’t start a fire without it, but it’s generally considered kosher: CLT boosters say that if contractors know how to work with the material, timber is just as safe as steel. Despite their widespread use, concrete industry groups strenuously object to the use of “combustible materials” in construction. One industry group has launched an email campaign to ostensibly make members of the AEC industry aware of (non–fire-treated) wood’s shortcomings. These emails are part of an ongoing battle between the wood, concrete and steel industries, a conflict which seems to have escalated in concert with the growing popularity of CLT and the introduction of the timber innovation act, which would provide government support to the development of mass timber technology. With ominous subject lines like “Georgia Bill Would Leave Savannah Exposed to Hurricane Threat” and “Flames Quickly Consume Combustible Denver Apartment Complex Under Construction,” the emails seem to sow doubt about the durability and safety of timber buildings. The five-story, 84-unit Denver building detailed in the latter missive was under construction when it was engulfed by fire. “Combustible materials have no place in mid-rise housing projects, regardless of whether they’re under construction or fully operational,” said Kevin Lawlor, spokesperson for Build with Strength, which initiated the campaign, in the email. “These buildings are effectively tinderboxes on steroids, and when a fire breaks out, they’re incredibly difficult to extinguish.” Build with Strength is a partnership convened by the National Ready Mixed Concrete Association. As their names suggest, both groups are unabashedly pro-noncombustible materials, concrete and steel included. Reached by phone, Lawlor said Build with Strength doesn’t have a beef with wood—it just wants to fulfill its mission of educating the AEC industry on the benefits of ready-mixed concrete and its use in low- to mid-rise buildings. Its members include architects, engineers, steel and concrete interests, political leaders, and even religious organizations. “It’s not a materials fight,” Lawlor said. “The goal is to promote safer construction in three- to seven-story buildings. The notices are not specifically designed to go out and attack any particular industry.”
Posts tagged with "Timber":
Sixty-three trees, 67 cross-laminated timber (CLT) panels, and 12 days—that’s what it took for Seattle-based atelierjones to erect the firm’s 1,500-square-foot CLTHouse, one of the first all-CLT residences constructed in the United States. The three-sided home is built on a leftover 2,500-square-foot triangular lot in Seattle’s Elliot Bay neighborhood on the shores of Lake Washington, where architect Susan Jones launched her research house experiment back in 2015. The house’s blackened, shou-sugi-ban treated exterior panels contrast with the blonde, white-washed, and daylit-spaces within the home, which emanate from a three-level circulation core containing a staircase, wet walls, and concealed utilities. The rustic home is inspired by the Northwest’s ubiquitous log cabins and features exposed wood paneling inside and out in homage to this building type. The approach, according to Jones, seeks to project a sense of “living with nature in the city” and provides a productive example of the smaller-scale capabilities of emerging CLT technologies. The house is punctured by triangular, gable-shaped windows that infuse it with daylight. Combined with the gypsum, plastic-laminate, stainless steel, and quartz-lined interior surfaces, it provides an “immersive, visceral, and natural experience,” according to the architect. Constructed using CNC-milled, rapidly renewable, and sustainably harvested CSFI-certified spruce, pine, and fir panels made by Structurlam, the building is crafted to inspire a sense of naturalistic escape and relaxation. The home’s exposed knotty pine aesthetic is reflected in a pair of stylized second-floor screened window walls that mark a triangular notch carved into the structure. Here, two pairs of sliding glass doors along the ground floor open the dual-lobed plan to the outdoors. Dining and living room spaces swing around this interior corner, where on one side, a thin plywood partition separates the dining and kitchen spaces from one another. Behind the kitchen sits a short hallway that connects the building’s backdoor entrance—located below a cantilevered bedroom suite—with the stair core. On the floor above, a trio of bedrooms, two bathrooms, and a reading nook cap off the home’s living areas while a rooftop deck overlooks the entire neighborhood from a wooden perch. The pilot house was developed as a research prototype and required extra municipal approvals to account for building codes that had not yet incorporated mass timber structural systems. Though crafted from sustainable materials from the start, atelierjones went one step further and planted 800 trees in conjunction with the project to act as an additional carbon sink. The result, according to Jones, is simply “hypernatural.”
Researchers at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland, are giving timber construction a mechanical leg up with the introduction of prefabricated, robotically-assembled timber frame housing. Together with Erne AG Holzbau, a contracting firm that specializes in timber, researchers at the institute’s Chair of Architecture and Digital Fabrication have developed Spatial Timber Assemblies, a system for digitally fabricating and constructing complex forms from timber. After a model of the structure has been laid out, robotic arms mounted in the ceiling of the assembly chamber are capable of building the required parts as well as putting them together. First, one arm picks up a beam and holds it while a human trims the piece into the proper size and shape. Then, a second robot arm pre-drills the holes needed for attaching the beam to the structure; finally, both robot arms work together to precisely place the beam as a human attaches it. Thanks to algorithms developed by the researchers, the arms are able to constantly recalculate their location in space and how to move forward without bumping into each other (or humans on the job site). A major advantage of Spatial Timber Assemblies is that the structures built this way carry their load-bearing capacity structurally, and don’t require reinforcing plates or any additional steel. If the overall design changes during construction, researchers are able to calculate a new, optimized framing solution using load-distribution algorithms. The system is more than theoretical. ETH researchers are currently using it to assemble six unique modules, which will join to frame the top two floors of the experimental DFAB HOUSE in Dübendorf, a suburb of Zurich. Once installed on site, both floors will have distinct rooms across 328 square feet of floor space. The final design, which uses 487 individual beams, will be wrapped in a clear plastic facade so that the underlying timber structure can remain exposed. Advancements in robotic construction are advancing rapidly, and ETH researchers have been developing robots that weld, spray concrete, and stack bricks to create forms that would have been difficult to build previously. And if the ETH needs help decorating the interior of their research house, robots can now assemble IKEA furniture, too.
After tackling an underwater restaurant in the south of Norway late last year, Snøhetta has unveiled plans for a “floating” hotel in the country’s north. “Svart,” named after the adjacent Svartisen glacier, will produce more energy than it consumes thanks to the Arctic Circle’s 24 hours of sunlight during the summer months. Reminiscent of the space-aged Apple Park doughnut, the ring-shaped Svart will rise from the waters of the Holandsfjorden fjord via crisscrossed timber columns and would provide guests with panoramic views of the lake and surrounding Almlifjellet mountain range. A round, wooden boardwalk will be suspended between the support struts and guests can stroll above the lake in the summer months; the path will be used for canoe storage in the winter, negating the need for an additional boathouse. The circular construction references Norwegian vernacular architecture, and draws inspiration from both the “fiskehjell” (a wooden, A-shaped structure for drying fish) and the “rorbue” (a type of traditional seasonal house used by fishermen), as fishing poles informed the wooden support design. Wood panels will also be used to clad the hotel’s exterior. As part of preserving the fragile natural landscape around the hotel, Svart will generate all of its electricity on site. Meeting Powerhouse standards (a collaboration meant to stoke energy positive building construction) will be accomplished both through design as well as technology. The hotel’s circular edge is rimmed with private terraces, which will set the building’s façade back and shade against solar insolation in the summertime, while the floor-to-ceiling windows will let sunlight passively heat the interior in the winter. The roof will be clad in locally produced solar panels, made with clean hydroelectric power, and the building will be constructed from materials with a “low embodied energy,” such as wood, meaning that a minimum amount of energy went into producing them. In designing the shape of the building’s roof, Snøhetta optimized the panels’ orientation to best take advantage of the “midnight sun” effect, where the sun never sets during the summer months in the Arctic Circle. Geothermal wells connected to heat pumps will warm the building in the colder months. Altogether Snøhetta estimates that Svart will use up to 85 percent less energy than a hotel of comparable size. “Building an energy positive and low-impact hotel is an essential factor to create a sustainable tourist destination respecting the unique features of the plot; the rare plant species, the clean waters and the blue ice of the Svartisen glacier,” said Kjetil Trædal Thorsen, Founding Partner at Snøhetta, in a press release. Svart is being developed in collaboration with tourism company Arctic Adventure of Norway, consulting firm Asplan Viak, and Skanska. Together the four companies make up Powerhouse, a group dedicated to advancing the construction of “plus houses,” buildings that produce more energy than they consume over a 60-year period, including the usage of building and demolishing the structure. No estimated completion date has been given at the time of writing.
Thanks to a two-year, $250,000 Wood Innovations Grant from the United States Forest Service, and with further support from the National Hardwood Lumber Association, Indiana Hardwood Lumberman’s Association, and the Indiana Department of Natural Resources, IKD is currently working on an advancement that may completely change the cross-laminated timber (CLT) market. Currently, CLT is made primarily of softwoods, which have the advantage of being fast growing and inexpensive. IKD believes the future of CLT should also include hardwood, and now it just might. As a proof of concept, IKD has constructed a large installation, which stands as the first hardwood CLT structure in the United States. The project was built with an experimental CLT material made from low-value hardwood-sawn logs for Exhibit Columbus, the new architectural exhibition in the modernist mecca of Columbus, Indiana. A reference to the conversation pit in the Eero Saarinen–designed Miller House, the IKD’s Conversation Plinth is a multilevel occupiable installation in the plaza in front of the I.M. Pei–designed Cleo Rogers Memorial Library. The motivations behind using hardwood are two-fold. Currently, over 50 percent of the 80 million cubic feet of hardwood harvested in Indiana each year is used for low-value industrial products. By integrating this wood into the higher-value CLT, it raises the value of what is already Indiana’s largest cash crop. And from the perspective of designers and engineers, hardwood CLT provides the possibility of a more fire-resistant panel and a form-factor advantage. “We are currently exploring a number of applications that could have larger scale building applications,” IKD partner Yugon Kim said. “Since hardwood has superior mechanical properties, we believe we can achieve a panel that could be thinner to meet the same structural capacity of an equivalent softwood CLT panel.” The Conversation Plinth is not simply an exhibition piece for IKD. It is a test of the hardwood CLT the firm developed with SmartLam, the first CLT manufacturer in the United States. Over the months, the project will be subjected to the varied and sometimes-extreme weather of south-central Indiana, providing firsthand data that IKD and SmartLam can use to advance their research on the material. From the beating sun of late summer through the sleet, snow, and ice of winter, the project will be monitored for durability as well as aesthetic and structural changes. “We are closely observing the mixed-species panels and seeing how they react in the extreme temperature and moisture fluctuations so that we can continue to refine the species mix within the panel, the adhesion process, and the finish application and approach,” Kim explained. “It is really interesting to see how differently hardwood moves from softwood when the moisture content varies, and we are looking deeper at the fiber structures and unique characters of species themselves as well to create a superior CLT panel.” The project continues much of the timber research IKD has been doing, including its design for the Timber City at the National Building Museum in Washington, D.C., and work on timber modular waste units, a timber version of CMU made from timber waste that has won numerous awards. Resources Project Lead and Designer IKD CLT Fabrication SmartLam Timber Engineering Bensonwood Phase One Hardwood Testing Material Supplier Pike Lumber Company Phase Two Conversation Plinth Hardwood Material Supplier Koetter Woodworking General Contractor Taylor Brothers Construction Co. Softwood Material Supplier And Fabricator Sauter Timber
If the steady stream of newly announced mass wood projects is any indication, mass timber building technologies are poised to take the American construction and design industries by storm over the next few years. As products like cross-laminated timber (CLT), nail-laminated timber (NLT), glue-laminated timber (glulam), and dowel-laminated timber (DLT) begin to make their way into widespread use, designers, engineers, and builders alike are searching for the best—and sometimes, most extreme—applications for mass timber technologies. But rather than reinvent the wheel, American designers can look to experienced mass timber designers in Europe and Canada for key lessons as they begin to test the limits of these materials in the United States. European and Canadian architects and researchers have long been at the forefront of mass timber design, starting with early experiments in the 1970s. By the 1990s, researchers like Julius K. Natterer at the Federal Institute of Technology in Lausanne, Switzerland, were developing initial CLT prototypes. Natterer’s work has been buttressed by that of many others, including research performed at the Norwegian Institute of Wood Technology under Thomas Orskaug and experiments conducted at the Technical University of Munich under Stefan Winter. One key lesson European timber projects teach is that when it comes to structural systems, weight matters. On average, mass timber assemblies weigh between one-third and one-fifth as much as concrete structures, despite equivalent structural capacities. As a result, mass timber buildings are much lighter than concrete ones, a positive for building in tricky urban situations, for example—where underground rail yards, subway tunnels, and municipal utilities place limits on how heavy and tall buildings can be. London-based Waugh Thistleton Architects (WTA), for example, recently completed work on Dalston Lane, a 121-unit CLT midrise complex located above a tunnel serving the Eurostar train line in the city’s Hackney neighborhood. For the project, the architects worked with timber-engineering specialists Ramboll to develop a stepped tower cluster rising between five and ten stories tall. CLT panels are used for the external, party, and core walls of the building, as well as the stairs and the building’s floors. The variegated massing is due directly to the architect’s use of CLT construction, which resulted in a lighter building that allowed the designers to build taller without more extensive foundations. The resulting building, with its staggered massing, better maximizes daylight infiltration into apartment units. The added height allowed the architects to add 50 more units to the project than originally permitted, a testament to just how light CLT can be. Andrew Waugh of WTA said, “Timber buildings are just simpler, cheaper, and nicer [than concrete ones]. High-density urban housing should be built using mass timber.” Lighter mass timber buildings also perform better in seismic zones. Since the lighter buildings carry less inertia, the potential for catastrophic swaying goes down. The strategy was applied this year with the Brock Commons tower, an 18-story, 400-bed college dormitory designed by Vancouver-based Acton Ostry Architects for the University of British Columbia Point Grey campus. The tower is made up of a hybrid structural system that includes CLT floor slabs, glulam columns, steel connectors, and dual concrete cores. The concrete cores anchor the light mass wood structure in place, helping to counteract seismic and wind-generated forces. The 173-foot-tall structure is currently considered the tallest mass timber building in the world, and the construction is particularly multifaceted, utilizing a specifically fabricated set of interdependent building materials and finishes to meet structural and fire-safety regulations. The Brock Commons tower’s hybrid structural system brings to light another valuable lesson: that above certain heights—ten to twelve stories—the lightness of mass timber construction becomes a liability with regard to wind loads. The lack of physical mass at the highest parts of a prototypical timber tower results in increased deflection from wind loads. Ola Jonsson, partner architect at Swedish architecture firm C.F. Møller, recommended architects “go back to thinking about construction when designing mass timber structures,” as a way of rethinking approaches to dealing with difficult-to-manage structural conditions. He added, “It’s so early [in the adoption of mass timber technologies] that few really know how to do it well.” The architect said that with certain tall timber tower projects the office is working on, designers had to develop new massing strategies to limit wind loads. Jonsson continued, “Many engineers lack experience in mass timber, so architects have to become central figures in construction and design during this early phase of adoption.” The firm is currently developing over ten mass timber projects, an emerging body of work that came out of earlier mass timber competition entries developed by C.F. Møller that took the world by storm. C.F. Møller recently entered into a partnership with HSB Stockholm—Sweden’s largest housing association—to design a series of new mass timber housing towers, including the 34-story Västerbroplan tower designed with concrete cores and wraparound terraces. The tower’s columns and beams will consist of a blend of CLT and solid timber. The building’s terraces will come with integrated exterior curtains and will be fully enclosed by a steel superstructure containing glass panels. The tip of the building is designed to dematerialize as it steps back along two facades, creating a series of exposed terraces and planted areas. Like Brock Commons, Västerbroplan tower features a hybrid structural system that is “resource-effective,” according to Jonsson, meaning both lightweight and rigid. The firm is also at work on a 20-story bundled housing tower called Hagastaden for HSB Stockholm, this one designed as part of a new quarter of the city that will contain mixed uses and generous pedestrian areas. The tower features varied floor heights designed to accommodate divergent uses like student flats, penthouse apartments, and typical family-occupied units. Aside from the firm’s multiple mass timber projects, C.F. Møller is working as part of an interdisciplinary research team that is developing new strategies around mass timber towers rising 20 stories or more. The group—backed by SP Technical Research Institute of Sweden, Växjö Municipality, and Linnaeus University, among others—will investigate mass timber construction from a fire-safety, life cycle, and construction technology perspective. Regarding the research project, Jonsson explained, "Massive wood constructions give urban planners, architects, and designers great possibilities to develop innovative and sustainable architecture,” adding, "but a broader knowledge and more practical experience in the industry is needed." Another paradigm-shifting impact mass timber construction has had on European building methods relates directly to the construction process. Because mass timber elements are factory-produced to order, the relationship between engineer, builder, and architect is extremely integrated. Cory Scrivner, mass timber specialist with Canadian mass timber manufacturer Structurlam, said, “For us, it’s all about the 3-D model. [Digital modeling and coordination] are all done before we go into production in the factory: Everything has already been approved by the architect, engineer, and our team.” Scrivner explained further that the intense coordination was necessary, as “we are designing a building made from components that are accurate within one to two millimeters of the digital model.” The designers behind Brock Commons utilized Structurlam as the mass timber manufacturer for the project. The advanced level of project coordination and off-site fabrication meant that project was finished roughly four months ahead of schedule, with a time-lapse video on a project website showing construction crews erecting upward of two floors per day. The first story for the project was built from cast-in-place concrete, while the remaining 17 stories are built in mass wood. The structural system utilizes glulam columns, steel connectors, and a two-way spanning CLT flat-slab. The design creates a floor beam–free structure that could be erected start-to-finish in nine and a half weeks. The rapid-fire construction time line, however, comes at the expense of longer planning and design phases prior to any work boots hitting the job site, as the teams must become absolutely synced prior to fabrication. Waugh of WTA explained that often with timber buildings, the firm asks its clients to “give us more time now [in the planning stages of construction] and we’ll save you even more time on the back end.” Waugh added, “The better programmed the construction process, the faster and more accurately the buildings come out.” Waugh said that after erecting several mass timber structures, the firm had “gotten so much better at it” than when they first started. One area of improvement has been material usage, which decreased with each project as the structural capabilities of mass timber have been further explored, tested, and certified. The Dalston Station project mentioned earlier, for example, utilized about two-thirds as much timber as the firm’s first mass timber project erected a decade ago. Part of the reason for the improvements, Waugh and Jonsson agreed, results from designers’ greater awareness of and comfort with the construction process. “To design well in mass timber, you need an architect who wants to understand that the nature of [the architect] is one of a ‘master builder’ as well as one of a ‘master designer,’” Waugh explained. Since mass timber construction methodologies are based on kit-of-parts assembly systems of mass-produced panel types and structural elements, there has been increased interest among European and Canadian firms in building high-density mass timber housing. These experiments have positive implications for the many American cities burdened with housing shortages and long project-approval times. Waugh explained that WTA’s focus rests on expanding the abundance of available housing through mass timber construction. He said, “We design everything in our office now as if it was a mass timber project. Concrete projects are becoming more and more rare.” Several projects in the works, like Shigeru Ban’s recently proposed 19-story Terrace House in Vancouver, Michael Green Architecture’s 35-story Baobab building in Paris, and PLP Architecture’s 80-story addition to the Barbican housing estate in London, point toward a wider adoption of tall and supertall mass timber housing towers. With faster construction times and fabrication that can occur in tandem with permitting, mass timber has the potential to help cities add housing rapidly, safely, and efficiently. Waugh added, “Humanity is becoming more urban, so the principal job of an architect in the 21st century is to develop high-density urban housing. In an era of climate change, it behooves you [as a designer] to reduce the amount of carbon emitted. Again, for us, mass timber is a way to do that.”
Michael Green Architecture (MGA) is a leader in the design of mass timber structures. The firm, jointly based in Portland, Oregon, and British Columbia, Canada, has been a pioneer in mass timber construction since the early days of glulam. Now, as mass timber technologies proliferate and gain wider acceptance, MGA is poised to make the next great leap in mass timber construction: full-fledged mass timber automation and prefabrication. “All of our projects are made from wood,” Michael Green explained over telephone, before adding that 95 percent of the firm’s work is specifically built using mass timber. The approach is due mostly to preference, as Green is a trained millworker who began his career decades ago working for renowned architect César Pelli designing “big buildings in steel and concrete around the world.” Those whirlwind experiences left the architect starved for ways to reengage with natural materials and craft, so after returning to his native Canada, Green opened his own wood-focused office. Throughout the early mass timber era, the architect was among the first to consider its widespread use and architectural potential. Today, the office focuses on utilizing mass timber elements in a variety of building types—for example, when tight urban conditions call for compact and efficient structures. The firm also works with institutional clients seeking long-term facilities and “100-year” buildings, which mass timber can easily provide. Green sees working in mass timber as “an opportunity to insert a lot of passion” into building projects that work as explorations in industrial design and are planned with a keen understanding of how they will be put together. This industrialized construction process suits Green, who explained that construction remains the last “major industry left on Earth that is still craft-oriented,” meaning that every building is built essentially as a one-off, custom prototype with none of the cost-saving benefits of industrialized factory production. That’s where mass timber comes in—building components are produced to order in controlled factory settings, where weather, temperature, and other variables are tightly relegated. The firm is currently working with technology start-up Katerra, which is looking to utilize the potentials of mass timber to automate and integrate the construction process nationwide. Wood Innovation and Design Centre MGA recently completed work on the Wood Innovation and Design Centre in Prince George, British Columbia. At the time of its completion, the nearly 97-foot-tall, six-story structure was the tallest all-timber structure in the world. The lower three floors of the project contain facilities for students pursuing wood-focused engineering degrees while the upper floors house governmental and wood industry–related office spaces. The building is clad in an elaborate system of louvered wood shutters that are optimized by exposure to mitigate solar glare. Aside from the structure’s mechanical penthouse, there is no concrete used in the building. Instead, the “dry” structure integrates CLT floor panels, glulam columns and beams, and mass timber walls into a complex design that conceals electrical and plumbing services within its relatively thin floor panels. North Vancouver City Hall The renovation and expansion of a municipal City Hall structure in North Vancouver, British Columbia, is one of the firm’s earliest mass timber projects. The 36,000-square-foot renovation bridges a repurposed 1970s-era structure and an existing library building with a new double-height mass timber and glass atrium. The 220-foot-long space is topped with CLT roof joists propped up on large CLT columns. Where the atrium meets the existing offices, clerestory windows provide views between public and business areas. The exterior of the long and narrow addition is clad in charred wood—a material that also wraps the exterior surfaces of other building elements—creating a new and dramatic exterior courtyard. Empire State of Wood As part of MGA’s early mass wood experiments, the firm worked with Finnish wood and paper group Metsä Wood on their speculative wood initiative. For the project, the firm was tasked with redesigning an iconic steel structure using mass timber elements. Naturally, MGA chose to envision the Empire State building as a mass timber tower, replacing steel girders and beams with glulam structures joined by metal plates. With slight modifications to the existing tower’s structural design, MGA was able to pull off a mass timber replica that matched the Empire State Building’s height inch for inch. Réinventer Paris/Baobab Tower The firm’s Réinventer Paris project proposes a large-scale, 35-story mass timber tower complex that would span over Paris’s Peripherique highway belt. The innovative and speculative proposal attempts to explore a new model for high-density housing that encompasses a variety of functional uses—market-rate and social housing, a student-oriented hotel, and a bus depot—dispersed throughout a series of high- and midrise timber structures. The timber towers feature CLT columns that frame indoor-outdoor verandas, with lower buildings clad in wood louver assemblies.
This is the fifth column of “Practice Values,” a bi-monthly series by architect and technologist Phil Bernstein. The column focuses on the evolving role of the architect at the intersection of design and construction, including subjects such as alternative delivery systems and value generation. Bernstein was formerly vice president at Autodesk and now teaches at the Yale School of Architecture. The topic this week in my practice class is “Scope of Services,” where we examine the architect’s relationship to the client’s work, to wit: What, exactly, does she have to do to deliver the project? The idea of “Basic Services” is central to explaining traditional practice, in that it’s the way we routinize our efforts through standard stages of effort (schematic design, design development, and so forth), structure decision-making, and, almost as important, create a basis for protecting our limited fees and invoicing the client. The idea of basic services or even “phases of design” has been under pressure for some time, mostly under the delaminating influence of technology. Long gone are the hand-drawn, single-line diagrams that once comprised the end product of schematics, just as transferring design intent to a builder may include BIM data or digital geometry in addition to traditional two-dimensional construction documents. The fluidity of digital data, and the purported insight that accompanies it, has blurred and expanded the system boundaries of services themselves. Nowhere is this more apparent than in the latest thinking about the use of mass timber as a fundamental building material for cities, work pioneered by my faculty colleague Alan Organschi of Gray Organschi Architecture. Alan argues persuasively that there is an opportunity to rethink the systems of carbon, energy, material production, design, and construction by the thoughtful and systematic use of engineered lumber—a renewable resource—in urban construction, where the forest is not just another source of raw material but also a place to store carbon. His thinking is not unlike Kiel Moe’s at Harvard, who posits that buildings aren’t independent objects that merely coexist with the systems that produce and sustain them, but rather are integral parts of those systems. Architects should ignore the resulting system boundaries created by constructs like, for example, the idea that our work be something called “Basic Services.” Both Organschi and Moe believe that architects must change the scale of their influence beyond the materialization of form by understanding, incorporating, and (dare I say it) controlling the flows of capital, energy, materials, and production. We need to replace our understanding of the supply chain with an overt ability to create and optimize it. This idea is immediately appealing, harkening back to the original assertions of modernism and its putative benefits for production and society, but equally daunting and intractable. This is precisely why Organschi’s claims about mass timber are so important: They represent a clear “through-line” from the means of making to the creation of form that is at the heart of the architect’s design proposition. Architects have always been part of a systems-design problem, and today’s digital tools that allow the representation, analysis, and optimization of systems fit perfectly into these new responsibilities. The digitization of design has blurred the traditional boundaries of our “systems of service,” but there are new opportunities emerging as design is informed by new technologies like systems engineering, big data analysis, and optimization, machine learning, and integrated network design. These tools will wend their way into innovative practices like Organschi’s, necessary to increase the architect’s understanding of and span of control over the supply chain. Organschi’s work thus challenges the entire idea of “Basic Services” as it currently drives practice—calling into question the roles of technology, research, professional certification, even the compensation to the architect for taking on such responsibilities. A “net zero” building means nothing if the systems that delivered it generates huge amounts of unaccounted carbon. We’ll need to reconsider and remediate all the systems boundaries of design—our internal protocols and processes and our relationship to the supply chain—to have true influence on the implications of our buildings. The efforts around mass timber described in this issue are some of the best thinking on this front so far.
AN Midwest Editor Matthew Messner spoke with Daniel Safarik, editor for the Council on Tall Buildings and Urban Habitat (CTBUH), about its “Tall Timber: A Global Audit.” The audit documented proposed, under-construction, and built tall buildings that use mass timber as their primary structural materials. The Architect’s Newspaper: What Prompted the CTBUH to conduct an audit of timber projects around the world? Daniel Safarik: We track all kinds of tall building construction routinely for the Skyscraper Center database and for our Global News feed on our website. The first well-publicized tall timber building was Stadthaus in London, which was completed in 2009. We noticed what seemed like a spike in announcements of timber tall buildings being proposed and constructed about four years ago , and everything that has happened since has reaffirmed this impression. When we saw the buy-in from the U.S. government represented by the U.S. Tall Wood Building Competition, in October 2014, that confirmed the impression that this really had momentum behind it, so we committed to tracking the two resultant projects through to completion. Unfortunately, the New York project was canceled due to market feasibility concerns, but the Portland project is now under construction. So the momentum began to build from that point, and we formed a Tall Timber working group in late 2014. The group started working on a design manual in mid-2015, and that effort has now gotten a turbo boost with the audit and the upcoming workshop at our 2017 conference, which is bringing together a lot of the key participants. Were there any interesting surprises once the information was gathered? The most striking thing was the diversity of construction methods that are being used to create these buildings, which are specific to local jurisdiction and the nature of the timber supply in each region. Of course, herein lies the difficulty of generalizing about what’s going on in tall timber worldwide, as well as coming to a consensus about classification and best practices—that is our challenge. What are some of the interesting discussions happening around mass timber? It’s encouraging to see the range of proposals, from both a stylistic and construction standpoint. The primary discussions revolve around fire safety and code, sustainability, and the feasibility of modifying fabrication techniques from mass production of stick-built single-family and platform-framed low-rise buildings to something that is workable for high-rise. What do you think the next steps are, or barriers to overcome, for mass timber to become a common building method? The foremost obstacle is local fire codes. Most fire codes prohibit wood structures from rising above five or six stories. Many codes stipulate that a building of this height must also have a concrete base, particularly if there are commercial uses on the ground floor, such as restaurants, or if there is vehicle parking, to give one to three hours of fire protection that would allow safe exiting before structural collapse. This is predicated on the assumption that wood high-rises would use platform construction, with dimensional lumber such as two by fours, beams, and joists, similar to those currently permitted. The key to mass timber’s viability as a structural material for tall buildings lies in its name. Massive wood walls and structural beams and columns comprised of engineered panels have demonstrated fire performance equal to concrete and, in some cases, superior to steel. Wood unquestionably burns, so there would be smoke issues, as with any fire, which would require proper sprinklering, pressurization, and other tactics used in tall buildings today. But mass timber has to burn through many layers before it is structurally compromised—basically it “chars” long before it collapses. As more jurisdictions come to appreciate the aesthetic, economic, and environmental advantages of tall timber, fire codes are expected to change. The second-biggest obstacle is a lack of standardization of construction materials, methods, and definitions. There are many forms of mass timber, and a wide degree of variance in approach when it comes to supporting tall timber structures. Thus, there is a range of techniques, from assemblages of highly similar panels for both floors and walls, to complex column/beam/outrigger combinations, such as are found in high-rises of steel and concrete. There are numerous proprietary systems, and the connections between elements also vary widely—often it is the location and orientation of the steel connectors between wood elements that can make all the difference in how long a structure can withstand fire or seismic action, and thus determine its feasibility under local code. Are there any proposals, speculative or real, that you are particularly excited about? I like the one we published in the CTBUH Journal for Chicago: the River Beech Tower. It would be great to see that go up in our home city.
Situated just one block west of the architecturally rich University of Chicago, the DuSable Museum of African American History is undertaking a major preservation effort. Located directly across from the Daniel Burnham–designed DuSable, the Roundhouse, a former horse stable also designed by Burnham, has laid vacant for over 40 years. Yet over the past decade, the DuSable Museum has worked to convert the heavy timber and stone structure into additional exhibition space. The DuSable Museum began working on converting the building in the mid- 2000s only to have the project stall thanks to the economic recession in 2008. By 2009, a renovation of the building’s exterior was complete, but the interior was left far from the museum-quality space the DuSable was hoping to achieve. To bring the 61,000-square-foot space up to museum standards, it would cost upward of $35 million. Unable to raise those funds, the project has taken a new direction, which will see scaled-back goals completed in the coming years. Starting with a $582,000 outdoor space, the Roundhouse is now able to host events and exhibitions for the first time. Designed by Chicago-based Site Design Group, the outdoor area is the first step in connecting the Roundhouse to the museum’s main building with a pedestrian-friendly landscape. At the same time, the interior of the building has been cleaned, and has already hosted its first major art event. Though the original plan to convert the interior into white-wall galleries has been put on hold, crowds happily flocked to catch a glimpse of one of Burnham’s most utilitarian projects. Much to the joy of architects and preservationists alike, the soaring heavy timber dome has survived in excellent condition. The web of large pine timbers is supported by the limestone walls and cast-iron columns, which all look as though they were recently constructed. At 150 feet across, the space is a welcome addition to Chicago’s catalogue of impressive civic interiors. The Roundhouse was the site of this year’s edition of EXPO CHICAGO, which hosted large-scale installations curated by Paris’s Palais de Tokyo. Coinciding with the opening of the Chicago Architecture Biennial, the exhibition, Singing Stones, commissioned Chicago- and Paris-based artists to create massive works. The height of the space allowed for tall hanging pieces, while the round walls intensified another work, which utilized ambient sound. Yet another installation addressed the few windows, a clerestory near the dome’s pinnacle, with colored films, filling the room with rainbow light during the day. While the Roundhouse may never reach the level of museum refinement and environmental control previously planned, it will continue to be updated and made ready for more exhibitions and events. It is currently scheduled to be complete by the time the Barack Obama Presidential Center opens on the other end of the University of Chicago’s campus in 2021. The DuSable has already begun conversations with the center to ensure exhibitions in both institutions are complementary. Until that time, architects can only hope the museum will occasionally open as it has for EXPO, letting the world in to see just how architectural a horse stable can be.
Austin Sports & Entertainment, together with New York–based Bjarke Ingels Group (BIG) and Austin-based STG Design, has released a first look at plans for its 1.3-million-square-foot, multipurpose collection of interlinked stadiums. The new East Austin District bills itself as Austin’s first pro-sports stadium and will host workspaces, convention space, retail, medical facilities, and a huge music arena. Anchored by a 40,000-seat stadium designed for soccer and rugby games and a connected 15,000-seat multipurpose arena, East Austin District will be a loose collection of buildings covered by a shared, latticed rooftop. The checkerboard roof, taking inspiration from the Jefferson Grid, will segment each area by function while still allowing visitors to experience a variety of indoor and outdoor programs. Resembling enormous, overlapping shingles, the red photovoltaic roof will allow the district to be self-sufficient, and eventually export electricity to the rest of eastern Austin once the infrastructure is in place. “Like a collective campus rather than a monolithic stadium, the East Austin District unifies all the elements of rodeo and soccer into a village of courtyards and canopies. Embracing Austin’s local character and culture, the East Austin District is a single destination composed of many smaller structures under one roof,” said Bjarke Ingels, BIG's founding partner. Although each building greatly differs in function, they’re united through all-wood interiors that reference Austin’s characteristic barns and porches. Eight outdoor courtyards are interspersed throughout the district, further highlighting the connection to Austin’s porch and patio culture. Expected to be used throughout the year, the outdoor spaces will host public parks and plazas, food trucks, and smaller concerts. While BIG’s plans for East Austin District are still conceptual, Austin Sports & Entertainment has been pushing to raise funding for the project, although they have declined to disclose the projected cost. If successful, the district would be built over the site of the annual Rodeo Austin with the event moving to the development’s secondary arena. “We are in active discussions with leading global sports and entertainment organizations, including our partner Rodeo Austin as well as various corporations, to serve as anchors to accelerate the goals of the Spirit of East Austin Forum,” said Sean Foley & Andrew Nestor, co-managing partners of Austin Sports & Entertainment, in a statement. If investors for the project can be found, construction is expected to begin in 2018 and finish by 2021.
A national design collaboration led by Boston-based Leers Weinzapfel Associates and including Arkansas-based Modus Studio, St. Louis–based Mackey Mitchell Architects, and Philadelphia-based OLIN has created America’s first large-scale, mass timber interactive learning project, already under construction at the University of Arkansas. Working off of a “cabin the woods” concept, 708-bed Stadium Drive Residence Halls feature fully exposed, locally harvested wood structural elements. The residence halls are a pair of snaking buildings joined in a central plaza, and include classrooms, dining facilities, maker-spaces, performance spaces, administrative offices, and faculty housing. The five-story buildings, totaling 202,027 square feet, are clad in a zinc-colored paneling, while copper-toned panels are scattered along each floor that appear to float above the heavily planted backdrop. Inside, wooden columns, beams and cross-bracing are all displayed to present a sense of warmth, and to connect students with Arkansas’s local ecology. The halls terminate with large study rooms at the end of each floor, which light up at night and act as beacons for the rest of the campus. The panels were constructed from Cross Laminated Timber (CLT), while the structural columns and beams are made of glulam, where layers of wood all facing the same direction are laminated together under pressure. Each arched building curves around a courtyard or common park area and students enter the complex through a covered “front porch” at the northern building’s main entrance. The central gathering room that connects the hall’s two wings has been dubbed the “cabin,” and despite being relatively small, packs in a hearth, community kitchen, lounge spaces, and a planted green roof. Each hall also features a double-height ground floor lobby with floor-to-ceiling windows that allow uninterrupted views of the surrounding landscape. “The interwoven building and landscaped courtyards, terraces, and lawns; the beauty of timber structure and spaces; and the excitement of performing arts and workshop facilities will make this newest campus residential community a destination and a magnet,” said Andrea P. Leers, principal of Leers Weinzapfel Associates. Leers Weinzapfel is no stranger to working with timber, as its multidisciplinary design building for UMass Amherst wrapped up construction late last year. The project is expected to finish in 2019, and will anchor a new master plan for the University of Arkansas campus.