Posts tagged with "timber":

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Google fills a historic timber hangar with its sleek new Los Angeles office

The Spruce Goose, a derogatory nickname for the Hughes H-4 Hercules, only flew once, but the largest plane ever built (entirely out of wood, to boot) continues to live on in pop culture ephemera. The plane has found a permanent home in Oregon’s Evergreen Aviation Museum, but the Los Angeles hangar where the Spruce Goose was built is getting a second shot at life. Under the timber hangar’s four-story-tall roof, ZGF Architects has completed a voluminous open office for Google that celebrates the building’s aeronautical heritage. Inside the 450,000-square-foot Playa Vista space, ZGF has restored the building’s historic Douglas fir “spine,” a series of curved ribs that support the ceiling, using wood salvaged from the hangar. Any leftover wood was used for furniture throughout the office. The Spruce Goose hangar was the largest timber building in the world when it was completed, and ZGF and engineers Arup mostly kept true to that legacy by scattering wooden finishes throughout and leaving the ceiling exposed. An enormous ship-like structure at the office’s core anchors the circulation routes and staircases to each floor, and according to ZGF, creates a “unique building-within-a-building design.” The hangar had largely laid dormant until Google took it over as a tenant, though in the past it’s served as a soundstage for films like Titanic and Avatar. In renovating such a cavernous space, ZGF punched skylights throughout the 750-foot-long building’s roof to maximize the amount of incoming daylight. The office space also features plenty of aviation-themed conference rooms, a fitness center, cafes, a 250-person event space, and aerial boardwalks that connect the first, second, and third floors. A “perception sculpture” made up of 2,800 hanging steel balls has been installed in the central atrium, that, when viewed from a specific angle, reveals the airy shape of the Spruce Goose plane. The references to Howard Hughes’s and the site’s place in aviation history is also celebrated throughout with placards and stories about the building, the Spruce Goose, Google, and L.A. Although Google has approximately 1,000 employees in the city, it’s unclear how many will work out of the Spruce Goose office. ZGF is no stranger to designing for tech giants and is currently part of the team renovating Microsoft's Redmond campus. “Los Angeles is an ideal home for Google’s newest office,” said L.A. Mayor Eric Garcetti, who was on hand for a tour of the building over the weekend. “Our city is a hub of innovation, creativity, and homegrown talent that shaped the aerospace industry in the past and that’s redefining the tech sector today. “Expanding Google’s presence in Playa Vista connects an historic building with our dynamic future, a site that will serve as a hotbed of scientific excellence and economic success for years to come.”
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Knotted installation proposes ways to reduce timber waste

When a tree is harvested for wood, what happens to the pieces that aren’t ramrod straight? An installation designed by Cornell University’s Robotic Construction Laboratory (RCL) proposes an answer to that question and has used robotic fabrication to build a self-supporting structure from rejected wood cuts. LOG KNOT was commissioned as part of Cornell’s Council for the Arts 2018 Biennial and installed on Cornell’s Agriculture Quad on August 22 of 2018, where it will remain until December 8. The theme of this year’s Biennial is “Duration: Passage, Persistence, Survival." The closed-loop form of LOG KNOT, the interplay of a traditional material, wood, and a high-tech fabrication process, and the eventual silvering of the structure’s untreated timber, all directly address those points. On an AN visit to Cornell’s main Ithaca campus, RCL director Sasa Zivkovic (also of HANNAH) walked up and down the structure to demonstrate its strength. LOG KNOT was formed by harvesting irregular trees that would be normally passed over from Cornell’s Arnot Teaching and Research Forest, 3-D scanning each, and using their shapes to design a self-tensioning structure. Using a CNC mill, the logs were then cut into segments that would optimize the amount of stress they would experience, and joining notches were cut into each end. Thanks to the precision of the computer-controlled mill, the final structure was erected in-situ by hand, says Zivkovic. The RCL team was able to install LOG KNOT by having one person hold up a log segment while the next bolted it into place, all without the use of a crane. The final effect is of a single extruded log, even though LOG KNOT was built using two different species of wood. Only 35 percent of the wood taken from most trees is used in construction, typically the tree’s straight trunk. LOG KNOT, much as with the wooden portion of HANNAH’s forthcoming Corbel-Bacon Cabin in Ithaca, was built by using the natural contours of the trees to form the structure. While LOG KNOT may be a temporary installation, ultimately the RCL wants to use the same technique to cut back on wood waste in a way that creates aesthetic possibilities.
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This British mosque is structured with a flowering wooden lattice

In Cambridge, England, Marks Barfield Architects (MBA) is erecting a timber-structured mosque inspired by geometric design and landscaping found throughout the Islamic world.

The Cambridge Mosque Project, founded by Dr. Timothy Winter in 2008, purchased the one-acre site in 2009. Allées of cypress and linden trees ring the mosque, which occupies a symmetrical 27-feet-by-27-feet grid. The new house of worship will be able to accommodate approximately 1,000 worshippers.

In a statement to The Guardian, the deceased architect David Marks viewed the project as a shift from the “preponderance of Ottoman mosques” found throughout the United Kingdom. MBA saw an opportunity to design an Islamic center unique to the British community, with a massing similar to the surrounding Georgian terraces, featuring a height of three stories, brick elevations, and a subtle dome rather than a towering minaret.

For the project, MBA reached out to Swiss timber-construction specialist Blumer–Lehmann AG (BLA). Thirty free-form timber columns, built of curved glue-laminated beams, form the primary support structure of the Cambridge mosque. Each column flowers into a network of latticed arches and beams that is topped with a lightweight, 20,000 square-foot timber roof. Rows of circular skylights are embedded above the supporting columns, allowing for the significant diffusion of natural light throughout the prayer space.

Design-to-Production (DP), a Zurich-based firm at the forefront of building information modeling, was commissioned by BLA to optimize the timber structural system’s geometry, establish a pre-fabrication and assembly strategy, and develop a comprehensive 3-D model of the project.

Through parametric design, DP whittled down the project’s 6,000 structural joints to just 145 different timber parts. Then the firm plugged in their digital fabrication data to a 5-axis CNC milling machine to mass-produce the timber components along with pre-assembly instructions and drawings. After being transported 900 miles over land and sea to the United Kingdom, the components were assembled in under a month.

The onion-dome, with a base of arched clerestory windows, reaches a height of 30 feet and is placed atop the truss system made of glue-laminated beams.

Construction for the project should wrap up in 2018 and will open in January 2019.

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Oregon becomes first state to legalize mass timber high rises

Thanks to a recent addendum to Oregon’s building code, the state is the first in the country to allow timber buildings to rise higher than six stories without special consideration. Portland has become something of a hotbed for timber innovation as of late. Carbon12, PATH Architecture’s eight-story glulam and cross-laminated timber (CLT) tower with a steel core, recently became the country’s tallest timber building and was set to be surpassed by LEVER Architecture’s 12-story Framework. Alas, that project was put on hold due to mounting financial difficulties last month, but it seems the precedent that the project achieved in securing a building permit from the State of Oregon and City of Portland will live on. The timber allowance comes courtesy of Oregon’s statewide alternate method (SAM), a state-specific program that allows for alternate building techniques to be used after an advisory council has approved the “technical and scientific facts of the proposed alternate method.” The allowance comes after the International Code Council (ICC)–the nonprofit group that Oregon models its building codes after–established the ICC Ad Hoc Committee on Tall Wood Buildings in 2015 to explore the benefits and challenges of using timber in tall buildings. A Committee Action Hearing was held in April of this year, where the Ad Hoc Committee, made up of code experts, stakeholders, and industry members presented their findings. All 14 of the committee’s suggestions were adopted, introducing standards and best practices for fireproofing, the load-bearing potential of CLT and heavy timber, water resistance, sealing, seismic ratings, and more. Three new building classifications were introduced as a result: Type IV A, timber buildings permitted up to 18 stories and 270 feet tall, Type IV B, timber buildings with a maximum height of 12 stories and 180 feet, and Type IV C, which is permitted to rise nine stories and 85 feet tall at maximum. The shortest of the timber typologies is allowed to use exposed structural timber as an interior finish, whereas the tallest, type A, must enclose all exposed surfaces and include a three-hour fire-resistance rating for the structural elements. “We congratulate the State of Oregon on becoming the first state to provide building code recognition for construction of tall, mass timber buildings,” said American Wood Council President & CEO Robert Glowinski in a statement. “Mass timber is a new category of wood products that will revolutionize how America builds and we’ve seen interest in it continue to grow over the last several years. This action by the Codes Division Administrator helps code officials in Oregon by making provisions consistent throughout the state. In adopting this new method, Oregon has also recognized the significant environmental benefits that accrue from greater wood product use.”
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Portland reveals winner in public bench competition

Interested parties have been left standing around for an extra week while they wait to find out the three finalists of Portland, Oregon's Street Seats: Urban Benches for Vibrant Cities design competition. The announcement ceremony was rescheduled to avoid a potentially violent political protest at the adjacent Tom McCall Waterfront Park and eventually took place on August 9 in downtown Portland. Street Seats was an international competition to design new public benches for the city of Portland. Design Museum Portland organized the competition in partnership with Portland General Electric Company (PGE) and World Trade Center Portland (WTCP), which is also the site where the 15 semi-finalists have been installed. Nestled between the Willamette River and downtown, the contest aims higher than merely bolstering public seating. Juror Kregg Arntson, executive director of the PGE Foundation, hopes the seats "inspire people to come down and enjoy the community." Launched in January, the competition attracted over 200 international entrants, and many referenced the Pacific Northwest's rainy climate and penchant for locally sourced wood construction. In addition to basic physical and safety requirements, the design brief emphasized sustainable materials and innovative processes while requiring a 1/8th scale model and a video. Fifteen shortlisted entrants received $1,000 grants to fabricate and install their prototypes on site. Portland-based Kyle and Alyssa Trulen, a landscape architect and a videographer respectively, took the grand prize with their entry A Quiet Place to Sit and Rest. Inspired by author Shel Silverstein's "The Giving Tree," the bench reflects the design of a stump and protects the trees it's installed around from soil compaction and bark damage. The thermally treated pine and ash are also insect resistant. "The real purpose of the seat design is not merely protection," said the Trulens, "it's about the relationship of a person with a tree...in hope of a healthier urban environment for both." The runner-up, Fluid Wood, was the result of a collaboration between Portland-based architect Norberto Gliozzi and Axiom Custom Products. Fluid Wood comprises layers of laminated wood cut in an egg-like form. Another finalist by The Tubsters, from Berkeley, California claimed the people's choice award for Tub(Time), a cut-away bathtub containing hardened transparent resin representing the Willamette River and a topographical map of the downtown and central eastside. Passersby are encouraged to climb in and recline. The Design Museum, which hosted a similar Street Seats competition in Boston in 2013, was not the first to sponsor such a challenge in Portland. The City of Portland Bureau of Transportation (PBOT) had developed guidelines in 2012 based on similar programs in New York and San Francisco to convert on-street parking spaces to public use. During a 2014 collaboration with the Center for Architecture, Portland yielded two winning submissions for seating that were installed in the city's northeast quadrant. In the summer of 2015, Portland State University architecture students designed and built a seating structure downtown. PBOT canceled the 2016 competition for an uncharacteristically low response rate; however, PBOT's program still exists outside of the downtown area. This year's Design Museum Portland competition is unrelated to the City's previous efforts and was launched independently. Many passersby spontaneously stopped to try the seats and participate in the announcement ceremony after the unveiling, reaffirming Design Museum Portland's managing director Erica Rife's statement that it is "important to be a good neighbor and inspire this community to be closer"—a much-welcomed change from the previous weekend's police and protester standoff. The 15 seats and over 200 1/8th scale models will remain on view until February. Several seats—Fractal Rock by Holst Architects, B_tween Bench by Gamma Architects, and Fern by Yingjie Liang, in addition to the winner and runners-up—will remain installed at the WTCP while the others will be relocated to sites throughout Portland. An online exhibition and schedule of accompanying programs are hosted at designmuseumportland.org.
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This experimental concrete roof is half the weight of its peers

A research team led by Jamin Dillenburger, an assistant professor at ETH Zurich, has recently produced and installed a concrete ceiling shaped by 3D-printed sand formwork. Dubbed the “Smart Slab,” the 1000 square-foot ceiling is significantly lighter and thinner than comparable concrete ceilings. The concrete slab is a component of ETH Zurich’s ongoing DFAB House project. The DFAB House is a load-bearing timber module prefabricated by robots. According to ETH Zurich, Dillenburger’s research group “developed a new software to fabricate the formwork elements, which is able to record and coordinate all parameters relevant to production.” In effect, the design of the ceiling is the product of the team-created software rather than analog design or planning. Following the design and digital testing phase of structural elements, the fabrication data was exported for the creation of 11 pallet-sized, 3D-printed sand formworks. After fabrication, each segment was cleared of sand particles and prepared for concrete spraying. The spray consisted of several layers of glass-fiber reinforced concrete. At its thinnest point, the concrete shell is less than one inch thick. After hardening for two weeks, the 11 concrete segments were joined to create the approximately 15-ton floor plate. While the underbelly’s contours were formed by 3D-printed sand casts, the ribbed grid above was shaped by CNC laser-cut timber formwork. The load-bearing ribs, resulting from timber formwork, were outfitted with a series of tubes for the insertion of steel cables both horizontally and vertically. These post-tensioned ribs carry the principal load of the “Smart Slab.” In placing the principal load above the concrete shell, the research team was able to insert complex geometric features below. The “Smart Slab” is not ETH Zurich’s first execution of an ultrathin concrete unit. Earlier this year, the university fabricated an undulating, two-inch thick roofing unit for a new live-work space in Zurich.
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Trump’s timber tariffs divide the construction industry

Last November, the U.S. Department of Commerce under President Trump announced an average of 21 percent import duties on Canadian timber products entering the U.S. The announcement was greeted with mixed reactions within the construction industry; builders claimed that the tariffs would increase the cost of construction, and American suppliers argued that the domestic timber industry would benefit, expand, and keep wood prices low. Single-family home construction in the U.S. relies heavily on Canadian softwood for roofing and framing. In 2017, Canadian lumber yards supplied 28 percent of the U.S. softwood lumber market, and home builders have been the first to raise concerns about the new duties, which were in effect by January. The National Association of Home Builders (NAHB) claims that the imposed tariffs have added approximately $9,000 to the cost of single-family homes and up to $3,000 on multi-family homes. The NAHB doesn’t believe U.S. domestic production is capable of meeting the current market demand and that the tariffs only hurt native manufactures by forcing them to increase their lumber prices. The NAHB is calling for the Trump administration to resume talks with Canada to secure a more mutually beneficial long-term agreement. David Logan, director of tax and trade policy analysis at the NAHB, says that historically, the U.S. lumber field has never been able to support rapid housing growth. “Buyers are still buying from the distributors they’ve always sourced from despite the tariffs,” he said. “Domestic lumber production has increased marginally in the last year, but it’s not kept up with the housing demand in terms of percentages, so it’s hard to say that we’re meeting the challenge. This has always been the case. We can’t meet that need...not even close.” Logan also argued that larger lumber companies in the U.S. are profiting unfairly from the deal, citing the Seattle-based Weyerhaeuser, which owns 12.4 million acres of forest in the U.S. alone and manages 14 million acres in Canada, as well as West Fraser, a Vancouver-based company that operates 48 mills across both countries. The NAHB claims that these companies are able to reap the benefits of both markets under the current trade agreement and likely won’t be affected if things change again. “We say over and over again that we need predictable and stable supply. That means using Canadian lumber,” Logan said. “Diversification of operations in the biggest mills on both sides of the border has really hampered any progress towards talking further about this issue because they’re able to increase production and do well. Prices have been so high there’s not really room for anyone but the big players to have a seat at the table, whether they’re Canadian or American.” The U.S. Lumber Coalition (USLC) rejects these claims. “Since the duties were implemented," the USLC wrote in a statement last week, "U.S. lumber shipments have increased by about 1.4 billion board feet, roughly filling the gap left by the decrease of Canadian imports. U.S. companies continue to invest in expanding their production capabilities to mill lumber from American trees by American workers to build American homes.” Pleasant River Lumber, a small milling company based in Maine, isn’t experiencing the negative side effects that the NAHB claims is coming out of the current tariffs on timber. In fact, the company is on track to complete a $20 million expansion at two of its four sawmills in the next 18 months. As part of the USLC, Pleasant River Lumber sources 95 percent of its lumber within the state of Maine and takes a bit from New Hampshire and Canada as well. Owner Jason Brochu is pleased with the country’s newfound focus on local production and plans to take advantage of it. “Increased demand due to forest fires and hurricanes in other states, spiked prices from the duties, heightened transportation costs, and a strong housing market all factor in to establish a level playing field for lumber production in the U.S. right now,” said Brochu. “We can’t compete against the government or any larger mills without things being equal.” Pleasant River Lumber is capitalizing on the growing lumber market by adding 50 percent more capacity to its production facilities and hiring 40 new employees as quickly as possible. They plan to boost production of their dimensional lumber from 200 million to 300 million board feet annually with the upgraded equipment. More importantly, they’re investing in their framing mills to address the increased demand within the housing market. “We believe we’re pretty typical of most mills in the country at this time,” Brochu said. “Most mills in Maine specifically are adding shifts or putting more money into mills to increase volume. We’re confident that the duties protect our rights as producers in the U.S. and we feel like the laws are working the way they should.” Brochu also emphasized how “relatively insignificant” framing lumber is in housing construction. USLC said the same thing stating that lumber makes up only 2 percent of the cost of a new home—which in 2018 stands at $368,500.  Framing lumber isn’t the only wood material that’s used to construct new homes. Plywood, which has zero duties imposed on it, flooring, and other timber products are also increasing in price. New York-based specialty wood-product manufacturer Hudson Company said the niche wood market has been affected as well. Two of its most popular reclaimed-wood products, both of which feature Canadian imported lumber, have both been impacted dramatically, says owner Jamie Hammel. Sales of silver pine siding are down by 60 percent, while hand-hewn beams are down 40 percent. “The reason our business is not down by 60 percent,” he said, “is because we sell other things. But we've had to limit the amount of volume we import because of the tariffs and we’ve had to diversify our product line to adjust and will continue to do. We’ve had to source more products locally which I guess was the administration’s goal.” The timber tariffs against Canada were among the first official duties placed on another country by the U.S. government since Trump took office. In the ten years since the Softwood Lumber Agreement (SLA) was established in 2006, the U.S. Commerce Department has allowed Canadian companies to sell lumber to the U.S. market at subsidized prices, lifting previously countervailing and anti-dumping duties as long as prices stayed above a certain figure. The SLA expired in 2015 and since then both countries have been unable to negotiate a new deal.   On behalf of the NAHB, Logan said that his organization doesn't foresee a new Canada-U.S. deal happening in the near future. “We don’t think the dialogue will reopen any time soon as long as the North American Free Trade Agreement negotiations are ongoing. If history repeats itself...the last time this happened it took around 5 years to settle,” he said referring to the original SLA. “Hopefully I’m wrong and this is done very quickly. Until then, prices will maybe get a bit higher, but volatility will certainly increase.”
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Yale University and UN Environment design self-sufficient tiny home

Yale University and Gray Organschi Architecture have designed and built a self-sufficient tiny house for UN Environment and UN Habitat, and the building is on display in UN Plaza in Midtown Manhattan until August 11. The Ecological Living Module contains 215 square feet of occupiable interior space and carves out another 16 square feet for a rear mechanical closet. The unit uses passive lighting and moisture collection, structural cross-laminated timber (CLT), food-growing green walls, and sun-tracking solar panels to shrink both the building’s embodied energy and resource needs. According to UN Environment, housing construction worldwide uses 40 percent of all resources produced every year and accounts for one-third of greenhouse gas emissions (not to mention the conflicts being fought over rapidly dwindling materials like sand). The module was commissioned just in time for the United Nations High-level Political Forum on Sustainable Development, to illustrate the idea that sustainable urbanization can only be accomplished if buildings minimize their contribution to climate change. The Yale Center for Ecosystems in Architecture and Gray Organschi worked together to design and install the module in only four weeks. The building was fabricated partially in New Haven and partially in Brooklyn and assembled on the UN campus amidst heavy security and tight construction restrictions. In order to balance maximum sun exposure with thermal comfort, the module was designed with New York’s specific micro-climate in mind. The dramatically-sloped building is clad in dark cedar planks and is home to two cascading “farm walls”, one on either side, and Gray Organschi claims that in New York the home can produce over 260 servings of vegetables. Plants were used inside as well in the loft area, and a living wall in the upper loft area purifies air for the inhabitants. “Structure was used as finish,” explains Gray Organschi founding principle Alan Organschi. The same pale CLT used to support the building was left exposed inside to create all of the finished surfaces, from countertops to stairs. The timber was sourced from the northeastern U.S. and sequestered more carbon than the effort used to harvest it. The team optimized daylighting in the building by carving strategic cuts into the back and roof. An Integrated Concentrating Solar Facade was installed to both reduce the amount of incoming sunlight and harvest solar power; an array of tiny panels track the sun’s movement and focus light on the minimally-sized solar receivers. The team wanted to build a system that could be assembled with the least amount of effort, and that would use the minimal amount of toxic materials to create. After August 11, the Ecological Living Module will be partially disassembled and brought to San Francisco; the structure was built narrow enough to be towed by truck. After that, the module will be flown out for demonstration in Quito, Ecuador, and then Nairobi, Kenya.
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Cross-laminated timber passes its first real-world blast test

Timber construction continues its march to mass market feasibility following a series of live blast tests on full-scale cross-laminated timber (CLT) structures. Through a series of tests conducted at the Tyndall Air Force Base in Florida, the WoodWorks Wood Products Council and U.S. Army are putting together guidelines for framing buildings with CLT. As Engineering News–Record reports, the idea to test CLT for its blast resistance properties arose after developer and construction company Lendlease entered into an agreement to build hotels on army bases across the U.S. As Lendlease chose to frame some of their hotels with CLT to save on time and construction costs, they were told that CLT wasn’t explicitly mentioned in the Unified Facilities Criteria, the building code for the U.S. Army. This meant that the material would have to pass a battery of durability and security hardening-related tests before it could be applied in any real-world structures. While the Army allowed the construction of Lendlease’s first CTL hotel, the Redstone Arsenal in Alabama, any future timber-framed buildings would require full-scale testing on a physical mockup before it could be approved. Lendlease reached out to WoodWorks Wood Products Council, who arranged the seven blast tests, Karagozian & Case Inc. (KCI), who developed and followed through on both phases of the testing, the Air Force Civil Engineer Center, and the University of Maine. The tests were carried out in two phases–the first in late 2016, and second at the end of last year. Lendlease built the testing structures, each of which were exposed to successively larger blasts over a period of seven tests; two of the mock buildings were 27 feet tall with two-foot-tall parapets and window cutouts at 12 feet, and the third was 23 feet tall, with two-foot-tall parapets and window cutouts at 10 feet. Both “buildings” had 15-square-foot footprints. After exposing the structures to 32 pounds, 67 pounds, and 199 pounds of TNT (with 610 pounds used for the last test), KCI concluded that for blast exposure, CLT was equivalent to the standard steel-studded wall. Because CLT panels contain multiple laminated layers, the remaining wood provides additional strength at the point of rupture. The load from the blast is also more evenly distributed owing to the panel’s support on all four sides, allowing the force to be evenly distributed towards the joints. The U.S. Army Protective Design Center (PDC) has already released their report on the 2016 tests and will follow it up with their analysis of the second round of testing this June.
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As mass timber’s popularity grows, the concrete industry goes on the offensive

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.”
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Seattle-based atelierjones creates one of the first all-CLT residences in the United States

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.”
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Swiss researchers use robots to build complex timber structures

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.