Posts tagged with "StructureCraft":

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Engineers describe their most innovative timber projects

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AN surveyed some of the leading practices in timber structure and facade engineering about the most innovative projects they worked on over the past year. Their responses highlight advanced applications of timber, ranging from a hybrid tower underway in Canada to greenhouse domes popping up in China.
Paul Fast  Founding Partner, Fast + Epp
Perhaps the most groundbreaking project we have been working on this year is Moriyama & Teshima Architects and Acton Ostry Architects’ The Arbour, a new ten-story building for George Brown College in Toronto. It features a novel structural system consisting of the slab-band arrangement commonly used in concrete construction but replaces most of the concrete with mass timber. Composite CLT-concrete slab bands with an overall thickness of 15.5 inches span 30 feet between large 1.4-foot- by-3.9-foot timber columns, and infill 6-inch- thick CLT panels clear span 15.5 feet between the slab bands. Central stair and elevator cores consisting of steel columns and diagonal bracing provide lateral resistance for the building. The end result is a primarily timber construction floor system that offers a thickness and flat soffit comparable to concrete construction but with a sharp reduction in both embodied carbon and construction time. The exposed timber flooded by ample daylight will also create a wonderful physical work environment for students and faculty.
Eric McDonnell Principal, Holmes Structures
I have been lucky enough to work on a number of innovative mass timber projects this year. These include Redfox Commons, designed by LEVER, which utilized salvaged timbers to create a connecting building between two refurbished historic warehouses; District Office, a six-story mass timber building designed by Hacker that is the future home of our Portland office; NIR Center, designed by Hennebery Eddy, a proposed ten-story hybrid structure of mass plywood floor panels and steel DELTABEAMs utilizing the new Type IV-B heavy timber build- ing regulation approved for the 2021 International Building Code; and the Adidas North American Headquarters expansion project, also by LEVER, which is using a unique hybrid structure of mass timber floor cassettes and precast concrete beams and columns. The most innovative of all would likely be Katerra’s Catalyst Building in Spokane, Washington, the first project to use CLT panels made in Katerra’s new manufacturing facility. This five-story office and classroom building is constructed almost entirely of mass timber, including CLT ribbed floor panels, glulam beams and columns, and CLT cladding panels, along with the first use of CLT shear walls utilizing buckling-restrained braces as ductile hold-down elements.
Chris Carbone Company Steward and Engineer, Bensonwood
Two projects come to mind: the River Road Barn by Sylvia Richards and Christopher Smith, and Haus Gables by Jennifer Bonner of MALL. Richards and Smith used a cross-laminated timber (CLT) floor plate and shear walls with glulam joists and concrete as the podium for the elevated mainframe, which was built with small black spruce glulams. The barn offers a 34-foot-by-46-foot clear span with 13-foot- 6-inch head height below a stainless tie. A semi-rigid moment-resisting joint was implemented at the rafter eave connection. Behind the elegant diagonal siding and bracing, bronze mesh keeps the bugs out.
Bonner’s house features playful crashing gables to span a narrow building, where the reflected plan of the folded plate roof defines the floor plan below. In places, the CLT roof plates even reach down through interior walls to hold up the second floor. All of the structural components—walls, roof, and second floor— are built with European CLT. The stair stringer and guardrails are also built from structural CLT. Specifications and communication about predrill angles and locations for the crew installing the connections from the roof through to the walls below were challenging, but fun! Andrew Lawrence Associate Director and Global Timber Specialist, ARUP
We enjoy experimenting with new wood-based materials and were lucky to be invited by Matthew Barnett Howland, Dido Milne, and Oliver Wilton to collaborate on their Cork House in which interlocking cork blocks provide structure, insulation, a weather barrier, and finishes. The low density of the cork presented several engineering challenges—we used the weight of the skylights to hold down the cork roof pyramids under strong winds, and we incorporated several layers of timber ring beams to hold the pyramids in shape. Utilizing the same material for both structure and insulation was not without its challenges, as well; the denser the blocks, the stiffer they became, but the less effective they were as insulation. It was always going to be a careful balance between the different performance requirements.
Lucas Epp, Head of Engineering, Structurecraft
One of this year’s most notable projects is the Taiyuan Botanical Garden in the Shanxi province of China, by Delugan Meissl Associated Architects (DMAA), out of Vienna. This project comprises three domes functioning as greenhouses for exotic plants. In each dome, a slender timber lattice grid shell supports the glass-clad enclosures. The largest dome spans almost 300 feet, making it the longest clear-span timber grid shell of its type in the world. StructureCraft is the structural engineer and builder for these three timber grid shells, working closely with DMAA to create a beautiful but efficient design, using the latest in parametric geometry and structural optimization techniques in Grasshopper and Rhino. All three parabolic grid shells comprise double-curved glulam beams, arranged in two or three crossing layers. When viewed from above, the timber structures resemble seashells, with the primary members closely bunched on one side and then fanned out across the surface of the domes. This complex geometrical arrangement means that every one of the members is unique. Digital fabrication techniques were key to realizing these structures, automatically generating the g-codes and assembly information for the more than 250,000 unique pieces and fasteners in them. The engineering team also carried out significant full-scale structural testing on the unique hidden connections used throughout the domes, working with our own structural testing lab as well as Tongji University.
The project is still under construction, with the structure of all three domes now complete.
Anne Monnier Principal, KPFF
While we completed several mass timber buildings over the past five years, the sheer quantity of projects getting to the construction stage last summer was a new record. Two projects in Portland Oregon—the Adidas North American Headquarters, designed by LEVER Architecture, and the District Office, designed by Hacker Architects—saw their structural frames go up this past year. The District Office features an innovative optimized, fiber-count mass timber frame that utilizes a tight colonnade column layout in one direction with long-span glulam beams. Not only does it allow for a clean, fully exposed, one-hour fire-resistance-rated mass timber frame for maximum daylighting, but it also enables organized routing of MEP systems.
frame for maximum daylighting, but it also enables organized routing of MEP systems. This is further developed by providing chases between CLT panels to allow for smaller distribution lines such as conduits and sprinklers. The Adidas expansion encompasses a more traditional column layout with double-glulam girders in the South Building and precast concrete girders in the North Building, both accommodating MEP routing through and/or over the girders coupled with a panelized CLT and glulam beam floor system. The speed of construction and fewer pieces to handle were key drivers on this fast-track project.  
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First dowel-laminated timber building in the U.S. set to open in Des Moines

A four-story mixed-use structure in Des Moines, Iowa, will be the first building in the U.S. to be constructed with dowel-laminated timber, an all-wood mass timber product that is held together without nails, glue, or fasteners and can be assembled with friction-fit wood connectors. Designed by Neumann Monson Architects, the 65,000-square-foot building, which houses shops, restaurants, and offices, is made from pre-fabricated 8'x20' DowelLam panels by StructureCraft, along with spruce glulam beams and columns, and precast concrete. DowelLam can reportedly be created in an array of custom profiles and is easily handled by CNC equipment. The architects reported that working with the easy-fit prefab panels allowed for faster construction with fewer workers. Not just structural elements, the panels will also remain exposed on the building in order to contribute to its overall aesthetic. In addition, the architects estimated that the timber construction “sequestered” around 280 tons of carbon and doesn’t run the risk of “off-gassing” chemicals like other glue-based mass timber products like CLT. Mass timber has been featured prominently in new construction as people are searching for alternatives to steel and concrete, with proponents touting its environmental benefits, among other positives. For example, Foster + Partners' sprawling plans for a new Silicon Valley neighborhood integrate mass timber throughout the site. People have been building bigger with it as well. This year a 280-foot-tall Norwegian tower claimed the title of world's tallest mass-timber structure. Mass plywood panels, another mass timber technology, were also recently approved for use in buildings as tall as 18 stories. StructureCraft reported other projects in North America are also putting the dowel-laminated product to use, including the Lake|Flato–designed Center for Conservation at the Museum of Fine Arts, Houston and a regional airport in British Columbia.
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Bing Thom Architects Takes the Stage in Washington, D.C.

A timber-backed glass facade provides transparency, acoustical isolation, and resiliency for a historic theater complex in the nation’s capital.

When the Mead Center for Performing Arts in Washington D.C. hired Vancouver-based Bing Thom Architects to double the institution’s square footage without disturbing two historic theaters designed by treasured architect Harry Weese, it was clear to firm principal Michael Heeney that standard solutions would not suffice. For one, the theater facilities were insufficient and outdated. More troublesome, however, was the fact that passenger jet liners taking off and landing at Regan National Airport across the Potomac River were so loud they were interrupting performances. The architects had to find a solution to mitigate this cacophony both for the existing structures as well as for the expansion—a new theater called Arena Stage. “We had to achieve acoustical separation and isolation from exterior noise in a way that was respectful and maintained the integrity of the original structures,” Heeney told AN. Building off an approach that originated from a project in Surrey, British Columbia, the design team decided to wrap the triangular-shaped complex in glass with timber column supports, topped off with a 500-foot cantilevered roof. With the help of structural engineers at Fast + Epp and facade consultancy Heintges, the team extrapolated the Surrey solution to provide even greater transparency for the existing Weese theaters, Arena Stage, and a variety of mixed use spaces totaling 200,000 square feet.
  • Facade Manufacturer Icon Exterior Building Solutions, DuPont, Viracon, StructureCraft
  • Architects/Consultants Bing Thom Architects, Heintges, Fast + Epp, StructureCraft
  • Location Washington, D.C.
  • Date of Completion late 2010
  • System timber-backed glass curtain wall with Krypton-filled insulated glass units
The system features a series of columns milled from parallel strand lumber to taper at the base with an ellipse-shaped section. Each column stands between 45 and 63 feet high with a diameter of 22 by 32 inches. Spaced on 36-foot centers, the columns effectively support the dead load of the glass curtain wall in addition to the weight of the roof overhead. The total perimeter of the complex measures approximately 650 feet in length. The base of each column tapers to a painted cast iron base featuring an ellipse-shaped cutout. “There’s enormous force coming down through those columns, but we articulated it gracefully like a ballet dancer en pointe,” said Heeney. The columns tilt four degrees to minimize glare. Icon Exterior Building Solutions custom designed and extruded the aluminum-framed curtain wall with 12- by 7 ¾-foot trapezoidal insulated glass units. A ½ -inch krypton-filled space is sandwiched by a 3/8-inch outer glass pane with a low # coating on the No. 2 surface, and a ¼-inch inner lite for optimal acoustic insulation. The entire system hangs from ½ inch steel cables connected to a structural steel top truss. Lateral loads are handled by a horizontal paralam mullion system (9 inches deep, 3/12 inches thick, 12 feet in length) that ties back to the columns with 5- to 6-foot paralam struts, depending on the curvature of the glass. “Normally with a curtain wall, you build the structure and it comes after, but here we used the columns to take the structure in addition to the glazing,” explained Gerry Epp, partner at Fast + Epp and president of StructureCraft. “It’s a super efficient scheme because we executed the structure at the same time as the facade.” According to Heeney’s estimation, the Mead Center’s large-scale commercial timber-backed glass facade was the first of its kind in the US and has performed beyond the designer’s expectations. When a 5.8-magnitude earthquake rattled the D.C. area in 2011, the glass curtain wall swung with the earth’s motion and then settled back into place. “Even though it’s not seismically designed, I think the West Coast designers’ inclinations made it inheritantly stable,” Heeney mused.
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Perkins+Will Canada’s VanDusen Gardens Orchid

StructureCraft fabricates an orchid-shaped roof that supports vegetation and Living Building Challenge principles.

After serving patrons at one of Vancouver’s oldest botanical gardens for nearly 100 years, the VanDusen Gardens Visitors Centre had fallen dangerously into disrepair. Perkins+Will Canada conceived of a new, orchid-shaped center that meets CaGBC’s LEED Platinum ratings, and is the country’s first structure to target the International Living Building Challenge with features like geothermal boreholes, a 75-square meter photovoltaic array, and a timber roof that supports vegetation. To help fabricate the wooden structure to Perkins + Will Canada’s vision, the team contracted StructureCraft, a Vancouver-based design-build studio specializing in timber craftsmanship and structural solutions. Initial designs for the 19,000-square-foot building were delivered to StructureCraft as Rhino files. The uniquely shaped rooftop, which mimics an outline of the indigenous British Columbia orchid, had to be economically fabricated in a way that took net carbon effects into account. Within Rhino plugins—mainly Grasshopper—and with the help of strucutral engineers Fast + Epp, the StructureCraft team sliced the shape of the building into 71 long, curved panels of repeatable geometries. “Each curve is unique, so there’s a different radii for each beam,” said Lucas Epp, a structural engineer who worked on the project. “We optimized the global geometry of the roof so the radii of all the beams were in our fabrication tolerances but still achieved the architect’s desired aesthetic.”
  • Fabricator StructureCraft
  • Designers Perkins + Will Canada
  • Location Vancouver
  • Date of Completion October 2011
  • Material Glulam, FSC-certified plywood, thermal insulation and vapor barrier, thermal barrier, mineral wool, fabric, moisture barrier
  • Process Rhino, Grasshopper, Autodesk, sawing, nailing, gluing, pressing
Also within Rhino, the team integrated all of the building’s services into each of the panels. Since much of the piping and wiring for other trades like insulation, sprinklers, and electric utilize flexible formats and conduits, modularizing the panels significantly reduced site time from months, to weeks. And to protect the wooden structures, moisture barriers and closed-cell thermal insulation were applied throughout. The parametric model was then imported to Solids modeling software to develop a bespoke fastening system. StructureCraft used jig and table sawing methods to mill panels of Glulam, chosen for its flexibility and strength. Timber battens were affixed as cladding in sizes that were thin enough to naturally accommodate the curves of each panel. Solid timber support columns, carved on StructureCraft’s in-house lathe, taper at both ends to Perkins + Will Canada’s design specifications. Business development engineer Brian Woudstra, who worked on the project, attributed the accuracy of fabrication and the speed of installation to the expansive capabilities of parametric modeling. “We could model every joist, Glulam panel, and ceiling batten to help with conflict detection and feasibility,” he said. “We always prefabricate our projects in our shop, so it’s like a kit of assemblies that all clicks into place.”