Mass Timber Winter 2021

Page 1

A semiannual publication by The Architect's Newspaper. Winter 2021

Mass Timber


The Architect’s Newspaper

Table of Contents



4 ICYMI 6 2021 U.S. Wood Design Awards 8 In Construction: Idaho Central Credit Union Arena 10 Studio Visit: Leers Weinzapfel Associates 12 Timber Map of the United States and Canada 16 Q&A: Jennifer Bonner and Hanif Kara

Publisher Diana Darling

East Editorial Advisory Board Paola Antonelli / M. Christine Boyer / Peter Cook / Whitney Cox / Odile Decq / Tom Hanrahan / Craig Konyk / Reed Kroloff / Peter Lang / Jayne Merkel / Signe Nielsen / Joan Ockman / Chee Pearlman / Anne Rieselbach / Terence Riley / Ken Saylor / Fred Scharmen / Jimmy Stamp / Mark Strauss / Claire Weisz

22 Timber Products Special Section

Executive Editor Samuel Medina

24 Case Study: Oregon State University College of Forestry 26 Fabrication: London Timber Pavilion 27 Products: Flooring and Decking 28 Case Study: Outpost 30 Products: Structural Mass Timber 31 Products: Cladding 32 Case Studies in Brief 34 Products: Timber Software 35 Products: Hardware and Fasteners 36 Resources

38 Comment: There’s More to Timber Building than Trees 40 Pictorial: NADAAA’s 2021 Venice Architecture Biennale Pavilion

Vice President of Brand Partnership Dionne Darling Director of Operations Matthew Hoffman

Managing Editor Jack Balderrama Morley Art Director Ian Thomas Web Editor Jonathan Hilburg Products Editor Adrian Madlener Associate Editor Matt Hickman Program Manager Katie Angen Contributing Editor Matt Shaw Events Marketing Manager Karen Diaz Graphics Manager Sarah Hughes Audience Development Manager Ankit Rauniyar

Editor’s Note

Timber, Timber, Everywhere This is AN’s third mass timber issue, and we’re running out of tree-related puns for headlines. We are not, however, wanting for sources of content. That’s because the field of mass timber, if broadly construed to include architecture, industry, and academic research and theory, continues to grow and find new conceptual and practical footholds. Mass timber’s ability to scale up and span typologies is readily evident in the following pages. So, too, is the diversity of structural timber products (page 22) available on the market. They include cross-laminated timber (CLT), nail-laminated timber (NLT), dowel-laminated timber (DLT), glulam, and laminated veneer lumber (LVL), among others. Indeed, the label “mass timber” itself contains many designations whose discrete advantages can get lost in this flattening. To be sure, flattening is one of engineered wood’s most distinguishing effects, and it’s one architects should embrace more, argues the designer and Harvard Graduate School of Design professor Jennifer Bonner in an in depth Q&A (page 17). Bonner and her collaborator Hanif Kara are unsatisfied with the substitution game they are seeing play out in the field, whereby conventional industrial materials (e.g., steel and ferroconcrete) are simply exchanged for wood products. The consequence of this, warns Kara, an engineer, is stultification. The pair are the authors of a new book that teases out—in ways both polemical and scholarly—CLT’s spatial implications by reconciling its most peculiar features as well as its limitations.

This is not necessarily to suggest creative approaches to form are lacking in mass timber. A glance at the winners of this year’s U.S. Wood Design Awards (page 6) should thoroughly dispel that notion, as should projects like Opsis Architecture’s new sports stadium (page 8) in Moscow, Idaho, and Skylab’s Outpost complex (page 28) in Portland, Oregon. And NADAAA’s installation for the 2021 Venice Architecture Biennale (page 40) offers evidence that architects are beginning to give CLT its due along the very lines that Bonner and Kara suggest. Moving past considerations of formalism and performance, architect and academic Kiel Moe contributes a thought-provoking critique (page 38) of the received wisdom surrounding mass timber. Its proponents, Moe argues, should expand their baseline conceptions of what it means to build with wood; to do so would acknowledge that it isn’t just trees whence CLT, DLT, glulam, and other products come but forests—and forests are not static. For example, their status as carbon sinks actually oscillates, depending on climatic factors as well as human activity. In some cases, they may even become sources of carbon emissions. Moe frames this investigative line in a planetary register to make timber building a “territorial” proposition. Construction is thus put in relation to larger ecological processes that can no longer be ignored. Such a prospect should be catalyzing rather than dispiriting, because it demonstrates what design can do in the world. It is also a reminder that, for all the good mass timber can do, it doesn’t get us out of the woods. Samuel Medina

Brand Partnerships East, Mid-Atlantic, Southeast, and Asia Tara Newton Midwest Account Executive Neill Phelps Ad Sales and Asset Management Assistant Heather Peters Media Marketing Assistant Shabnam Zia Special Projects Assistant MaHong Bloom

West Editorial Advisory Board Frances Anderton / Steve Castellanos / Teddy Cruz / Erin Cullerton / Mike Davis / Neil Denari / Priscilla Lovat Fraser / Devin Gharakhanian / Jia Gu / Betti Sue Hertz / Brooke Hodges / Craig Hodgetts / Walter Hood / Jimenez Lai / David Meckel / Kimberli Meyers / Anna Neimark / John Parman / Simon Sadler / Roger Sherman / William Stout / Warren Techentin Midwest Editorial Advisory Board Aaron Betsky / Robert Bruegmann / Sarah Dunn / Zurich Esposito / Martin Felsen / Sarah Herda / Reed Kroloff / Edward Lifson / Robert MacAnulty / Ben Nicholson / Donna Robertson / Raymond Ryan / Zoe Ryan / Elizabeth Smith / Julie Snow / Michael Speaks / Martha Thorne / Andrew Zago Southwest Editorial Advisory Board Anthony Alofsin / Marlon Blackwell / Nate Eudaly / Carlos Jiménez / Sheryl Kolasinski / Tracy Zeeck General Information: Editorial: Advertising: Subscription: Reprints: Vol. 19, Issue 3 | Winter Timber 2021 The Architect’s Newspaper (ISSN 1552-8081) is published 8 times per year by The Architect’s Newspaper, LLC, 21 Murray St., 5th Fl., New York, NY 10007. Presort-standard postage paid in New York, NY. Postmaster, send address change to: 21 Murray St., 5th Fl., New York, NY 10007. For subscriber service: Call 212-966-0630 or fax 212-966-0633. $3.95/copy, $39.00/year; international $160.00/year; institutional $149.00/year. Entire contents copyright 2021 by The Architect’s Newspaper, LLC. All rights reserved. Please notify us if you are receiving duplicate copies. The views of our reviewers and columnists do not necessarily reflect those of the staff or advisers of The Architect’s Newspaper. Cover photo: Karsh Alumni and Visitors Center designed by Centerbrook Architects, photo by Peter Aaron, story on page 32.

In 2021, AN is investing big in mass timber. Two virtual multi-day conferences will explore the merits and potentials of mass timber construction, whose impact is growing throughout the United States, from the Pacific Northwest to the Deep South. Each iteration of TimberCon will feature a wide-range of speakers— architects, engineers, and academics— who will foreground exemplary timber projects, identify best-case practices for their assembly, and spotlight emerging technologies within this exciting field, all while addressing the remaining industry hurdles mass timber faces in the years ahead. Timber, it’s clear, is growing on everyone. TimberCon is a virtual conference series developed by The Architect’s Newspaper and hosted in partnership with the Mass Timber Institute. The first iteration of the series will be held on March 18 + 19, with the second to follow on October 21 + 22. For more information on both events visit

4 In Case You Missed It...

The Architect’s Newspaper

We corralled the top timber architecture stories buzzing about the internet over the past year.

Zaha Hadid Architects gets approval for the world’s first timber soccer stadium Zaha Hadid Architects’ (ZHA) proposal for the Forest Green Rovers Football Club’s Eco Park Stadium in Gloucestershire, England, will finally move ahead. ZHA won the competition for the 5,000-seat stadium in 2016. The facility will anchor a 100-acre technology campus once completed.

Snøhetta will design the Theodore Roosevelt Presidential Library

Snøhetta’s design for the Theodore Roosevelt Presidential Library will be built in the badlands of North Dakota. The timber-framed structure will rise from the rugged landscape close to the town of Medora. COURTESY ZAHA HADID ARCHITECTS RENDERING BY NEGATIV

Koichi Takada Architects reveals treelike skyscraper for Downtown Los Angeles

Zaha Hadid Architects reveals a modular housing platform for Honduras

Katerra and Michael Green Architecture complete the Catalyst Building

Sidewalk Labs pulls the plug on its Toronto waterfront smart city

Australian firm Koichi Takada Architects has unveiled its design for Sky Trees, a 43-story tower set for the corner of 11th Street and Hill Street in Downtown Los Angeles. Most striking is the tower’s striated timber facade, which will be distanced from the window wall system to create an integrated rainscreen and sunscreen.

Zaha Hadid Architects has teamed with international engineering consultanting firm AKT II and Hilson Moran to develop a timber residential kit-of-parts for the Caribbean island of Roatán, off the coast of Honduras. The team is touting the many potential built configurations for the kits—up to 15,000.

The Catalyst Building, a new mass timber educational structure designed by Michael Green Architecture and built by Katerra, opened in September in Spokane, Washington. The 150,000-square-foot building is expected to meet net-zero and zero-carbon standards.

Citing “unprecedented economic uncertainty,” Daniel L. Doctoroff, chief executive of urban innovation start-up and Alphabet subsidiary Sidewalk Labs, announced in May that the contentious Quayside redevelopment project on the Toronto waterfront had been nixed. The project was heavy on timber construction and concern-prompting tech products.

New renderings of timber-topped terminal at Portland International Airport released

Portland, Oregon–headquartered ZGF Architects celebrated the 80th anniversary of its hometown air travel hub, Portland International Airport, by sharing early renderings of the upcoming main terminal, expected to be completed in 2025. The terminal’s timber roof will be studded with skylights.

Basket-inspired building for social housing is heading for Vancouver

Khupkhahpay’ay, a new social housing development for First Nations peoples designed by GBL Architects, has been approved by the Vancouver City Council. The nine-story building at 1766 Frances Street will be passive house–certified and will use a mix of steel framing and exposed cross-laminated timber floor plates.



Mass Timber Winter 2021

Adjaye Associates reveals new Princeton University Art Museum building Adjaye Associates revealed its design for a new Princeton University Art Museum building. The structure will replace the existing facility with a new one twice its size. In four pavilions at each corner of the new building, glulam ceiling structures will incorporate many of the rooms’ systems.

United States lumber prices reach record high

Lumber prices are still rising across the United States despite pandemic-related construction interruptions. One theory is that a glut of projects that were put on hold while timber mills were closed during the first months of the pandemic are now active and eating up timber supplies faster than mills anticipated.


Diller Scofidio + Renfro and Stefano Boeri Architetti tapped for Milan development

Milan-based real estate investment fund COIMA crowned Diller Scofidio + Renfro and Stefano Boeri Architetti the winners of an international design contest to fill Pirelli 39, part of a massive portside redevelopment in Milan. The new building will be built from structural timber and will be covered in 18,000 square feet of plants.

Michael Maltzan Architecture designs affordable mass timber residential tower

Michael Maltzan Architecture is designing The Alvidrez, a 14-story supportive housing tower in Downtown Los Angeles that will contain 150 studio apartments. The building’s massing was determined in part by the construction logic of its mass timber frame system.

SHoP reveals world’s tallest commercial hybrid timber tower for Sydney

Australian software giant Atlassian has shared plans for its new Sydney headquarters: a hybrid timber skyscraper designed by SHoP Architects in collaboration with Australian firm BVN. It will be the world’s tallest commercial tower of its kind at 590 feet. COURTESY DILLER SCOFIDIO + RENFRO AND STEFANO BOERI ARCHITET TI/RENDERING BY AETHER IMAGES

6 News

The Architect’s Newspaper

WoodWorks announces the winners of the 2021 U.S. Wood Design Awards From a cedar-clad, mixed-use complex hugging the Columbia River to a timber–topped tennis pavilion on the grounds of a storied Kansas City, Missouri, athletic club to a light-frame transitional-housing complex in Milwaukee with a gabled roofline and room for 16 families, the winning projects in this

year’s U.S. Wood Design Awards, presented by WoodWorks– Wood Products Council, are an appropriately eclectic bunch showcasing the sector at its most daring. The 2021 U.S. Wood Design Awards jury consists of Clare Archer, vice president and senior director of Gilbane Building

Company, Washington, D.C.; Kate Diamond, civic design director at HDR’s Los Angeles office; Julie Hiromoto, principal and director of integration at the Dallas headquarters of HKS; and John Mitchell, associate partner at Chicago-based Hartshorne Plunkard Architecture.

Commercial Wood Design—Low-Rise

Institutional Wood Design

National Winners Multifamily Wood Design



Timber Lofts Engberg Anderson Architects Location: Milwaukee Structural engineer: Pierce Engineers

The Discovery Center DIGSAU Contractor: Catalyst Construction Building type: Office Building system: Mass timber


Cakebread Cellars BCV Architecture + Interiors


Location: Rutherford, California Structural engineer: Kenneth Campbell Structural Engineer

Location: Philadelphia Structural engineer: CVM Contractor: INTECH Construction

Building type: Civic/recreational Building system: Light frame

Commercial Wood Design—Mid-Rise Contractor: Wright Contracting Building type: Commercial low-rise Building system: Mass timber and light frame

Durable & Adaptable Wood Structures



Oregon State University Forest Science Complex MGA | Michael Green Architecture

Outpost Skylab Architecture

Location: Corvallis, Oregon Structural engineer: Equilibrium Consulting, a Katerra Company

Location: Hood River, Oregon Structural engineer: Valar Consulting Engineering Contractor: Celio Contracting

Contractor: Andersen Construction Building type: Education Building system: Mass timber


Trefethen Historic Winery Taylor Lombardo Architects with Preservation Architecture Location: Napa, California Structural engineer: ZFA Structural Engineers Contractor: Facility Development Company

Building type: Commercial low-rise Building system: Timber frame and light frame

Building type: Commercial low-rise and office Building system: Mass timber and light frame

7 News

Mass Timber Winter 2021

Green Building with Wood

Jury’s Choice

Beauty of Wood


The Kendeda Building for Innovative Sustainable Design The Miller Hull Partnership in collaboration with Lord Aeck Sargent, a Katerra Company Location: Atlanta Structural engineer: Uzun + Case Contractor: Skanska USA


Building type: Education Building system: Mass timber


Freedom House Berners Schober Location: Green Bay, Wisconsin Structural engineer: raSmith Contractor: Immel Construction

Wood in Government Buildings

Building type: Institutional Building system: Light frame

Karsh Alumni and Visitors Center at Duke University Centerbrook Architects and Planners Location: Durham, North Carolina Structural engineer: LHC Structural Engineers Contractor: LeChase Construction

Building type: Education Building system: Mass timber and light frame


Jones Beach Energy & Nature Center nARCHITECTS Location: Wantagh, New York Structural engineer: Robert Silman Associates Structural Engineers Contractor: Scalamandre Construction

Building type: Civic/recreational Building system: Mass timber and light frame

Regional Excellence Winners 1040 W. Fulton Hartshorne Plunkard Architecture Location: Chicago

UCLA Margo Leavin Graduate Art Studios Johnston Marklee Location: Culver City, California

Tennis Pavilion Generator Studio Location: Kansas City, Missouri

Princeton University Embodied Computation Lab

Andy Quattlebaum Outdoor Education Center at Clemson University

The Living (design architect) and NK Architects (architect of record) Location: Princeton, New Jersey

Cooper Carry Location: Seneca, South Carolina

Cedar Speedster Weber Thompson Location: Seattle

Biomass Boiler Building AMLGM Location: Quincy, California

Church of the Incarnation Chapel Addition HH Architects Location: Dallas

Platte Fifteen OZ Architecture Location: Denver

8 In Construction

The Architect’s Newspaper

Palouse Undulations

Opsis Architecture and StructureCraft are shaping a freeform future for mass timber. Architect: Opsis Architecture Sports architect: Hastings+Chivetta Structural engineer of record, roof structure and timber fabricator: StructureCraft Structural engineer of record, base building: KPFF General contractor and construction manager: Hoffman Construction Manufacturers: Boise Cascade, PotlatchDeltic, QB Corp., Idaho Forestry Group, Tri-Pro Cedar Products Products: Glulam, CLT, DLT, plywood panels, Cedar Siding Moscow, Idaho, may not be the most auspicious venue for breakthrough architecture, but it’s where the future of mass timber is taking shape. There, at the University of Idaho, in the foothills of the Rocky Mountains’ Bitterroot Range, all number of mass timber elements have been marshaled into the freeform structure of the Idaho Central Credit Union (ICCU) Arena, whose undulating profile is a potent sign of progress for the industry. Designed by the Portland, Oregon–based firm Opsis Architecture, in collaboration with St. Louis’s Hastings+Chivetta, the 4,000seat arena incorporates long-span mass timber elements not seen anywhere else in the country. A hybrid structural system comprising glulam beams, steel king-post trusses, and concrete shear walls rises to form a broad canopy over a cast-in-place concrete seating bowl, itself ensconced in a trim of zinc-and-glass curtain wall. The rolling geometric motif picks up on the surrounding Palouse region, whose channeled scablands “were created by the cataclysmic Missoula floods at the end of the Ice Age,” explained Opsis founding partner and principal Alec Holser. The University of Idaho challenged Opsis to find ways to apply wood products in nearly every aspect of the arena’s design. Through relationships facilitated by the school’s Department of Forest, Rangeland and Fire Sciences, project stakeholders were able to source a significant share of those products—cross-laminated timber (CLT), dowellaminated timber (DLT), glulam, plywood, and cedar siding—from within the region and, in some cases, from within the campus itself: the architects were given the rare opportunity to source timber directly from the University of Idaho’s Experimental Forest, an 80-yearold growth maintained for pedagogical purposes. Further underlining this localist ethos, area manufacturers donated materials and use of fabrication facilities. As comprehensive as its design agenda was, the ICCU Arena is not Opsis’s first mass timber rodeo. The firm recently completed the Hidden Creek Community Center in Hillsboro, Oregon, which similarly integrates concrete shear walls to stretch the limits of post-and-beam glulam spans. The structural principles applied at Hillsboro are elaborated upon in Idaho, where Opsis deployed digital modeling software to reconcile a dynamic form with a range of programmatic and structural requirements. Following completion of the programming and concept design phases, Opsis and construction manager Hoffman Construction, in consultation with the client, tapped StructureCraft as engineer of record for the roof. The Vancouver, Canada–based firm, something of a one-stop shop for timber engineering and construction, was chosen



Top: Vancouver-based StructureCraft was the lead engineer for the roof structure and managed the fabrication of mass timber components. Here, a segment of the glulam central portal frame takes shape. Bottom: The free-form arena shell rests on a soaring structural system of glulam-and-steel trusses and is flanked and supported by concrete shear walls. The foundation doubles as a cast-in-place concrete seating bowl.

9 In Construction for its expertise in the design-build process and, importantly, engineering long-span and free-form timber structures. (It also fabricated much of the timber used for the project.) A key characteristic of mass timber construction is the relative straightforwardness of on-site installation, which, in many ways, resembles a gargantuan kit-of-parts. However, that effectiveness entails front-loaded costs in the design-build cycle. The architecture and engineer teams curbed these costs by defining their roles and coordinating project tasks early on. They held numerous collaborative design workshops to establish structural geometries, connections between components, and construction processes with schedule impacts. So almost as soon as Opsis formulated the roof shape, StructureCraft got to work on developing its complex structure. To do so, it drew on advanced computational design techniques in both Grasshopper and Rhino to generate and optimize the geometries of the double-curved roof structure, portal frame, and king-posted trusses, which reduced glulam volume and complexity and helped boost overall structural efficiency. “The team moved forward with a monumental, sculpted truss frame system constructed of dual wood members up to six feet deep and spanning 130 feet, which supports all of the ends of the primary long-span king-post trusses over the arena,” said StructureCraft engineering and 3D manager Lucas Epp. “Each of the beams in these portal frames transfers over 400,000 pounds of load into the frame legs, and the complex timber connections involved push the limits of current timber engineering and design.” Installation by Hoffman Construction commenced with the 60-foot-long and over20-ton central portal frame, which was lifted into place fully outfitted with mechanical systems by a 300-ton mobile crane. Next followed the king-posted truss sections, measuring up to 95 feet in length and hoisted into position atop the central portal frame. Lastly, the construction crew lifted and installed the more than 400 prefabricated plywood panels that make up the free-form roof surface. This plywood roof diaphragm, explained Epp, “clear-spans 250 feet from end to end of the arena and acts as the lateral bracing system for both wind and seismic loads.” The ICCU Arena is scheduled to open to the public in the fall, following the installation of all mechanical systems. From there, Holser hopes, “the new facility will provide a vibrant and intimate fan experience that showcases the region’s unique natural materials and landscape, all while serving as a forum for a variety of events to enhance campus student life, including concerts and convocations.” Matthew Marani

Mass Timber Winter 2021



Top: The arena’s undulating profile is intended to resemble the rolling hills of the surrounding Palouse geographic region. Many of the wood products used in the project were sourced within Idaho. Bottom: The roof diaphragm is composed of more than 400 prefabricated plywood panels and spans 250 feet. Its structural matrix also acts as a lateral bracing system, a useful feature in the earthquake- and high-wind-prone state.

10 Studio Visit

The Architect’s Newspaper

Leers Weinzapfel Associates The national mass timber leader talks about how it got started in the field and what it’s working on now.

Over the past ten years, Boston-based firm Leers Weinzapfel Associates has emerged as a leader in the United States’ burgeoning mass timber design industry. The studio first worked with cross-laminated timber (CLT) in 2013 when it began work on the John W. Olver Design Building at the University of Massachusetts, Amherst. More recently, in 2019 Leers Weinzapfel completed the University of Arkansas’s Adohi Hall, the largest CLT building in the U.S. and winner of many accolades, including a WoodWorks Design Award announced in AN’s 2020 timber issue.

Tom Chung, one of Leers Weinzapfel’s principals, said that the firm is bullish on mass timber for its many obvious, pragmatic advantages: it’s a renewable resource, has a less carbon-intensive manufacturing process than concrete or steel, and can be locally sourced across much of the country. But for Andrea Leers, cofounding principal, the material’s advantages go beyond economic or even ecological considerations. “The contentment that comes from being in a wood environment is a huge incentive,” she said. “The smell of the wood, the feel of it, the appreciation of it is something

rooted in human experience. Everybody knows wood. Everybody’s touched trees. It’s very immediate.” Chung agreed. “Andrea and I, as we’ve practiced, we’ve heard people say, ‘Oh, I don’t like this building because there’s too much concrete or too much steel. It feels cold.’ I’ve never heard anybody complain [about a building] that there’s too much wood.” Jack Balderrama Morley


1 The John W. Olver Design Building at the University of Massachusetts, Amherst 2017 Leers Weinzapfel’s first mass timber project, a new home for the University of Massachusetts, Amherst’s design programs, was originally supposed to use a steel structural system, but representatives from the school’s building construction and technology program suggested that the firm consider engineered wood. “We have always been a firm interested in

material research and development,” Leers said, “so we saw this as a great opportunity to learn a new building system.” Translating elements like 60-foot-spanning steel members into timber presented many challenges, and solutions like the massive zipper trusses in the main hall combine to create the firm’s most complex timber structure.

11 Studio Visit

Mass Timber Winter 2021

2 Adohi Hall 2019


Administrators at the University of Arkansas wanted Adohi Hall, a 708-bed dorm Leers Weinzapfel designed with Modus Studio, Mackey Mitchell Architects, and OLIN, to be a mass timber building from the project’s start. (With help from Walmart and Ozarks woodlands, Arkansas is becoming a center for mass timber construction.) So the architects closely adhered to local timber code restrictions, which limited the building’s height, and the dimensions of available CLT systems, which helped determine the dimensions of the living units. Because timber cladding can be difficult to maintain at this scale on a relatively tight budget, the architects opted for a “light metal jacket,” Leers said, but left wooden ceilings exposed in student bedrooms so the material would be felt throughout the building.


3 Kreher Preserve & Nature Center Preschool 2022, anticipated


Auburn University’s School of Forestry and Wildlife Sciences runs a small, nature-focused preschool that immerses children in the great outdoors. “For the students’ typical class day they’re running around in the forest observing nature, looking at the ecology, playing with animals and insects,” Chung said. “All the fun things that we all wanted to do at camps growing up.” The Alabama school tapped Leers Weinzapfel to design a hub for the preschool’s trail-based learning in the 120-acre Kreher Preserve in the city of Auburn. The site is less than 200 miles from a CLT plant in Dothan, which will turn trees cleared for the project into wood products and supply materials used in the building. Given the project’s forested site, the architects wanted to make as much of the building as possible out of wood. When finished next year, it will have wooden ceilings, walls, and floors; a CLT structure made of local loblolly pine; and wooden piles instead of a concrete foundation.

4 Innovation Center 2022, anticipated On the site of Suffolk Downs racetrack in Revere, Massachusetts, north of Boston, HYM Investment Group is building a multiacre, mixed-use complex, and the developers asked Leers Weinzapfel to design a small gateway building for the project. When it opens in 2022, the Innovation Center, as the building will be known, will have coworking spaces on its upper floors laid out in a 20-by-25-foot grid determined by the mass timber structure. “The signature piece is the roof canopy, a gently curving, sail-like, wave-cresting form that recalls the nearby Revere Beach,” Chung said. The roof will cantilever over a terrace that is part of the central public space for the development.


12 Mapping the Industry The timber industry in the United States has long been limited to smallscale projects by local building codes. But as the more permissive 2021 International Building Code gets adopted by states, taller structures are being allowed across the country. Investment like Canada’s funding to encourage the use of mass timber in affordable housing is helping mass timber evolve from a trend to enduring reality. In addition, the advances in seismic, fire, and structural research critical to timber construction are becoming more inclusive of the sustainable management needed to create healthy forests. We’ve updated our annual map, which continues on pages 14 and 15, of the schools, organizations, and manufacturers leading the way in mass timber research and development. These groups in Canada and the U.S. innovate quickly, which is why AN worked with the Mass Timber Institute, a global leader in sustainable mass timber research, and the U.S. Forest Service’s Wood Innovations Program to validate this list. Schools University of Northern British Columbia Prince George, British Columbia The University of Northern British Columbia’s Master of Engineering (MEng) in Integrated Wood Design is a unique, intensive yearlong program that focuses on modern wood structures. The MEng program is housed in the Wood Innovation and Design Center in downtown Prince George and features the Wood Innovation Research Lab, in which researchers test next-generation materials. The lab’s design meets Passive House standards. 1

University of British Columbia Vancouver, British Columbia The University of British Columbia is home to the 18-story Brock Commons Tallwood House. This student housing project was supported by the Canadian government’s Tall Wood Building Demonstration Initiative. The facility not only houses students but serves as a living lab where researchers study the long-term performance of mass timber structures. 2

Washington State University Pullman, Washington At Washington State University’s Composite Materials & Engineering Center (CMEC), students get hands-on experience with the design, testing, fabrication, and construction of cross-laminated timber (CLT) panels. CMEC has partnered with resin suppliers and construction companies, such as Katerra, to design, certify, and test mass timber systems for new and existing markets. 3

Oregon State University Corvallis, Oregon Oregon State University’s (OSU) College of Forestry is home to the TallWood Design Institute (TDI), a collaboration between OSU’s College of Engineering and the University of Oregon’s College of Design. At TDI researchers and practitioners drive research and education on advanced timber products manufacturing, design, and construction. TDI is working on projects focused on durability, serviceability, adhesives, seismic and structural performance, the fire performance of mass timber, and more. The Oregon Forest Science Complex, which incorporates extensive use of CLT, comprises OSU’s George W. Peavy Forest Science Center (featured on page 24) and A.A. “Red” Emmerson Advanced Wood Products Laboratory. 4

University of Alberta Edmonton, Alberta The Advanced Research in Timber Systems (ARTS) research group is part of the department of civil and environmental engineering at 5

the University of Alberta and is led by Professor Ying Hei Chui, who holds the NSERC Industrial Research Chair (IRC) in Engineered Wood and Building Systems. The ARTS group focuses its research on the next generation of mass timber construction with new connection techniques. Through the NSERC IRC program, the group is investigating the use of mass timber panels as lateral load resisting systems in balloon frame construction and developing design procedures and construction details for mass timber panels. In addition to the IRC program, the ARTS group is researching mid-rise light wood frame building systems and the development of innovative engineered wood products. Colorado School of Mines Golden, Colorado Working in collaboration with industry partners and other schools on this list, researchers at Colorado School of Mines are using a $1.7 million National Science Foundation grant to develop mass timber structures designed for seismic performance in earthquake-prone regions. With the goal of proving that sustainable timber buildings are just as safe as those built with more conventional materials and with higher resilience standards, the group has successfully tested a two-story building on the University of California, San Diego’s “shake table” and plans to test a full-scale 10-story structure in 2022 as part of the NHERI Tall Wood Project. 6

Organizations Forestry Innovation Investment Vancouver, British Columbia Publicly owned and funded by the provincial government, Forestry Innovation Investment is British Columbia’s wood products marketing agency. The agency works to sustain the Canadian timber industry by developing new market segments and export markets, advancing wood use and construction technologies, and marketing outreach to position forest products. 1

APA—The Engineered Wood Association Tacoma, Washington This nonprofit trade association represents and regulates engineered wood manufacturers in North America and promotes innovative solutions and improved practices. 2

Softwood Lumber Board (SLB) West Linn, Oregon The SLB is an industry-funded initiative established to promote the benefits and uses of softwood lumber products in outdoor, residential, and nonresidential construction. Programs and initiatives supported by the SLB focus on increasing the demand for finish and struc3

tural softwood lumber products in the United States as well as mass timber and hybrid building systems. Think Wood West Linn, Oregon Think Wood provides commercial, multifamily, and single-family home design and build resources to architects, developers, and contractors. In addition to its online educational resources, including e-books and continuing education units related to tall wood and mass timber, the organization identifies and profiles projects and professionals using North American softwood products in innovative ways. 4

Forest Business Network Missoula, Montana The Forest Business Network (FBN) helps businesses that manufacture, design, and sell products made from hardwood or softwood. FBN offers timber consulting services based on its expertise in “underutilized timber and woody biomass,” which include business assistance, grants, and custom reports. 5

The Architect’s Newspaper

CutMyTimber Portland, Oregon (Timber product processing) According to the U.S. Forest Service, CutMyTimber is among the top timber product processors in the United States—a growing subsector in the field of manufacturing. With offices in Portland and North Vancouver, Canada, the company uses CNC machines to create customized products and building systems for projects around the world. 3

Freres Lumber Lyons, Oregon (Mass plywood panels) Freres Lumber’s mass plywood panels (MPPs) are a composite, veneer-based engineered wood product that can be produced using 20 percent less wood than CLT panels. With its MPPs and mass plywood lams, Freres Lumber is certified to produce every structural element for a multistory mass timber structure. Specializing in small-diameter wood for engineered wood products, Freres now has an Environmental Product Declaration and a life cycle assessment that substantiates its closed-loop, environmentally sustainable manufacturing processes. 4

Rosboro Springfield, Oregon (Glulam, LVL, parallel strand lumber) Rosboro is the largest producer of glulam beams in North America. Other than its diverse range of Douglas fir glue-laminated timber products, it also produces sawn lumber and studs made from western regional tree species. All manufacturing takes place in two locations in Oregon: Springfield and Veneta. 5

DR Johnson Riddle, Oregon (CLT panels, glulam beams) DR Johnson was the first company in the United States to obtain American National Standards Institute (ANSI) certification to manufacture CLT panels. An affiliate company, Riddle Laminators, has been making glulam beams from Douglas fir and Alaskan yellow cedar for over 50 years. 6

Vaagen Timbers Colville, Washington (CLT, glulam beams) Vaagen Timbers uses high -tech milling machines to produce products at its Colville, Washington, facility, as well as at two other sites in Usk, Washington, and Midway, British Columbia. It uses lumber-scanning technology and a portable HewSaw machine to handle underutilized small logs. 7

Manufacturers Structurlam Mass Timber Corporation Penticton, British Columbia (CLT, glulam, GLT) Structurlam Mass Timber Corporation has manufactured components of buildings like Brock Commons Tallwood House at the University of British Columbia in Vancouver and the Carbon12 building in Portland, Oregon. With its partner Walmart, Structurlam is opening a plant in Conway, Arkansas, to support the retailer as the exclusive supplier of mass timber products for Walmart’s new home office campus. 1

StructureCraft Abbotsford, British Columbia (CLT, DLT, NLT, glulam beams, LVL, LSL, PSL) StructureCraft is an engineer-led construction firm that creates a multitude of mass timber products, including its signature DowelLam, the first all-wood panel manufactured without glue or nails in North America. Its team includes engineers of record, computational designers, fabricators, and builders. Bringing craft traditions to high-tech construction, StructureCraft partners with architects, owners, and general contractors across North America and elsewhere to engineer-build timber and hybrid structures. 2

Katerra Spokane, Washington (CLT panels, glulam beams) Katerra operates a 250,000 -square-foot mass timber manufacturing facility in Spokane, Washington. Its catalog of products, which are developed and tested in collaboration with the Composite Materials & Engineering Center at Washington State University, includes CLT panels for walls, floors, and roofs. 8

Western Archrib Edmonton, Alberta (Glulam) From two facilities in Boissevain, Manitoba, and Edmonton, Alberta, Western Archrib designs and manufactures glue-laminated structural products, including beams, columns, studs, and decking. It also provides custom fabrication with 3D-modeling software for CNC framing, steel connections, and finishes. 9

13 West

Mass Timber Winter 2021






7 2

10 8

3 3






4 4 5





SmartLam North America Columbia Falls, Montana; Dothan, Alabama (CLT panels) SmartLam produces CLT panels for floors, walls, roofs, and elevator shafts, and supports its products with design, engineering, and consulting services. The company owns two facilities in Montana and a Southern pine lumber factory in Dothan, Alabama. 10

Euclid Timber Frames Charleston, Utah (ICLT panels) Euclid manufactures interlocking cross-laminated timber (ICLT) for walls and roofs. Unlike CLT, ICLT panels are produced without the use of fasteners or adhesives, relying instead on tongue-and-groove and dovetail joints. 11

Planned Factories Kalesnikoff Lumber South Slocan, British Columbia (CLT panels, glulam beams) Kalesnikoff Lumber is opening a Can$35 million plant in South Slocan, British Columbia. The 110,000-square-foot factory is the 81-year-old company’s first foray into mass timber. 1

14 Mapping the Industry

The Architect’s Newspaper

19 8

16 15 9





3 4

8 11 18


12 13


16 15





13 14 15

Auburn University Auburn, Alabama The Southern Pine Design Lab is a joint venture between the architecture, engineering, and forestry departments that will research how mass timber technologies can be used to incentivize removal of hurricane-downed timber and the performance of steel-CLT hybrid mid-rise structures, among other things. Professor David Kennedy is working alongside Forestry Architecture Fellows on a portable mass timber solar kiln that will be used to help rural communities derive economic value from their resources and learn more about mass timber. The School of Architecture’s Rural Studio is researching thermal and energy effects of mass timber and has collaborated with McGill University on a recently published paper on mass timber breathing walls, construction of two mass timber test pods, and a current project that couples timber with thermal mass for buoyancy-driven ventilation.

17 2



Mississippi State University Starkville, Mississippi Timber Innovations for Mississippi Buildings Reimagined (TIMBR(R)) is a fourth-year undergraduate studio at Mississippi State University established in 2016 and funded in part by the Sustainable Forestry Initiative, the Mississippi Forestry Foundation, and Weyerhaeuser. The TIMB(R) studio asks students to study the benefits of innovative wood product design and building methods, and students compete to design timber structures across the country. Additionally, the class works with the Sustainable Bioproducts major within the College of Forest Resources to develop and test new products. 9








Laurentian University Sudbury, Ontario Laurentian University’s McEwen School of Architecture (MSoA), which opened in 2013, emphasizes timber architecture design and hands-on knowledge of wood craftsmanship in its curriculum. In 2017, the school completed a new building with a wing constructed of CLT that houses an atrium with a wood-burning fireplace, a classroom, and a lecture hall on the ground floor, the school's library on the second floor, and a green roof and terrace. The building, designed by Toronto firm LGA, won a 2017 Ontario Wood WORKS! Wood Design Award and a 2018 OAA Design Excellence Award, and MSoA hosted the first International Wood Educators Conference in September 2019, with keynote speaker Brian MacKay-Lyons.



Schools University of Arkansas Fayetteville, Arkansas The Fay Jones School of Architecture and Design at the University of Arkansas recently opened its new mass timber dormitory by Boston-based architecture firm Leers Weinzapfel Associates. Peter MacKeith, dean of the school, is spearheading the Wood Lab, which specializes in building and designing with wood. It is part of the school’s FAY Fabrication Laboratories. 7

Lakehead University Thunder Bay, Ontario A department within Lakehead University’s Faculty of Natural Resources Management, the school’s forestry program focuses on the technology behind contemporary forest management. Currently, the university is collaborating with the province of Ontario by mapping trees of the region’s woodlands. 8

George Brown College Toronto The Arbour is an upcoming 10-story academic building on George Brown College’s campus that will be made of mass timber sourced within Canada. Construction for The Arbour is set to begin this year and, once complete, the building will house the Tall Wood Research Institute, a forum for students and faculty to research and develop ideas related to mass timber construction. 12

15 East University of Toronto Toronto The University of Toronto has plans to build a Tall Wood Academic Tower that will reach a height of 14 stories. Designed by Patkau Architects and MJMA, the timber-and-concrete hybrid tower will serve as a mass timber demonstration project in Canada’s largest city. The country’s federal and Ontario governments provided initial funding for this initiative on the main campus in downtown Toronto. The tower is expected to be completed in 2022. 13

Clemson University 14 Clemson, South Carolina Through the Wood Utilization + Design Institute, Clemson University’s engineers and architects are innovating with mass timber through several grant-funded and studio projects, including those focusing on highway noise barriers, disaster relief housing, and rapid military-building construction. In late 2018, the university’s school of architecture patented the result of multiyear research into Sim[PLY], a wood construction system that the school has already used to build multiple structures. Virginia Tech Blacksburg, Virginia Researchers at Virginia Tech have been experimenting with mass timber for more than a decade. In 2018, faculty and students at the School of Architecture + Design designed a CLT train-watching tower as part of a tourism development plan in Radford, Virginia. Their project was completed in September 2019 and recognized by the AIA Blue Ridge design awards. 15

University of Ottawa Ottawa The University of Ottawa’s Department of Civil Engineering is home to a research program dealing with the response of mass timber systems to the effects of extreme loading such as wind storms, earthquakes, and blasts. For the past fifteen years, introductory and advanced timber design courses have been offered at the undergraduate and graduate levels. 16

University of Massachusetts Amherst Amherst, Massachusetts Within the Building and Construction Technology program at the University of Massachusetts Amherst, researchers received National Science Foundation and state funding to model and test advanced angle-ply CLT panels made with underutilized tree species Eastern hemlock and Eastern white pine. The research is conducted inside a CLT building designed by Leers Weinzapfel Associates featured on page 10. 17

Yale University New Haven, Connecticut The Yale School of Architecture offers a joint degree with the university’s School of Forestry & Environmental Studies that focuses on sustainable architecture alongside ecology and policy. The two schools have also partnered with local architecture firm Gray Organschi to support the Timber City research initiative, which is funded by the U.S. Department of Agriculture. Additionally, a number of interdisciplinary consortia within Yale have established platforms for mass timber research, including the Yale Building LAB and the Yale Carbon Containment Lab. 18

University of Maine Orono, Maine The Maine Mass Timber Commercialization Center based at the University of Maine is working with regional stakeholders to promote construction of mass timber buildings, promote CLT manufacturing through development of a business attraction package, support high performance grades from SPFs lumber, and conduct analysis of carbon impacts of mass timber construction. 19

Mass Timber Winter 2021

Organizations Mass Timber Institute (MTI) Toronto The MTI, located within the Daniels Faculty of Architecture, Landscape, and Design at the University of Toronto, is a partnership of academic institutions, government, and industry. The MTI’s mandate is to position Canada as a global leader in mass timber research and education and in the export of sustainable mass timber products. Its research and teaching interests include sustainability and society; building science and constructability; indigenous participation and reconciliation; manufacturing, design, and supply chains; trade and export diversification; and analytics and data synthesis. 6

Canadian Forest Service Ottawa The Canadian Forest Service is an arm of the Canadian federal-government department Natural Resources Canada. Operating from a central office in Ottawa and six other research facilities throughout the country, the service fosters environmental leadership, sustainable forest management planning and policies, and ongoing scientific research. 7

Canadian Wood Council Ottawa Much like its American counterpart, the Canadian Wood Council represents wood product manufacturers, develops design and technical standards, and works to ensure its resources are available to professional and academic communities. 8

Forest Products Association of Canada Ottawa The Forest Products Association of Canada represents the country’s paper, pulp, and wood industries nationally and internationally. They specialize in environmental leadership, forestry management practices, product innovation, workforce advocacy, and other economic and trade efforts. 9

Wood WORKS! Ottawa Wood WORKS! was created by the Canadian Wood Council to increase the use of wood construction for mid-rise and tall buildings in Canada. Wood WORKS! is a resource for education, training, and technical support for building tall with timber. 10

FPInnovations Pointe-Claire, Quebec FPInnovations, active in Quebec City, Montreal, and Vancouver, Canada, is a nonprofit timber construction research institute covering topics like forestry management and construction products. Currently, FPInnovations has a team devoted to advanced timber building systems, finding efficient acoustic and structural solutions for projects of every scale. 11

American Wood Council (AWC) Leesburg, Virginia The AWC is the leading voice for America’s structural wood products industry. In addition to advocating for public policies that benefit the wood industry, the AWC promotes opportunities for wood products and mass timber in codes and regulations. It also provides American National Standards Institute–accredited design specifications along with education and training on proper wood design and construction. The AWC is partially funded by the Softwood Lumber Board. 12

American Forest & Paper Association (AF&PA) Washington, D.C. AF&PA advances public policies and funds research to support the production of wood products in the U.S., particularly pulp, paper, and packaging. It also supports wood manufacturing across the globe and promotes sustainable growth of the U.S. forestry industry. It has collected data on the resilience of mass timber to promote acceptance of wood building systems. 13

U.S. Forest Service (USFS) Washington, D.C. As part of its mission to manage and protect national forests and grasslands, the USFS works with public and private agencies to build markets for sustainable wood products. One such product is CLT produced from dead and dying trees, the harvesting of which could help control the spread of forest fires. The Wood Innovations Program provides funding for projects utilizing CLT and other wood materials. 14

WoodWorks: Wood Products Council Washington, D.C. WoodWorks provides architecture, engineering, and construction professionals with free technical support related to the design and construction of commercial and multifamily wood buildings, including mass timber structures. WoodWorks also helps educate professionals about wood construction through events, publishes technical resources, and connects developers and project teams through the WoodWorks Innovation Network. WoodWorks is partially funded by the Softwood Lumber Board and the U.S. Forest Service. 15

Manufacturers Lion Lumber Phoenix, Illinois; Lufkin, Texas (CLT panels and CLT mats) Formerly known as Sterling Lumber Company, Lion Lumber is a 70-year-old family company that manufactures cut-to-length lagging lumber, industrial lumber for transportation project shielding, and pallets and skids for shipping and unloading. Specializing in CLT, Lion Lumber also offers design and build services for custom work. Last year, it opened a massive new facility in Lufkin, Texas, where it continues to make its signature TerraLam mat. 12

Texas CLT Magnolia, Arkansas (CLT mats) Texas CLT is an investor group that reopened the defunct Arkansas Laminating mill last year in Magnolia, Arkansas, where it produces CLT mats made from Southern pine and Douglas fir. 13

Timber Systems Lapeer, Michigan (Glulam, sawn timber) Timber Systems installs, fabricates, and designs mass timber structural components. With a wide array of timber products, its product catalog includes glulam and solid sawn timber, decking, bridges, and shelters. 14

Element5 St. Thomas, Ontario, and Ripon, Quebec (CLT,glulam, NLT, CLIPs, Boxx panels) Element5 is Canada’s newest and Ontario’s only CLT and glulam manufacturer. The company produces the widest-format panels of any CLT plant in North America. It also manufactures several value-added, CLT-based components including hollow-core floor and roof panels and Cross-Laminated Insulated Panels (CLIPs), which offer a prefabricated, high-performance building envelope that can be quickly assembled for rapid building enclosure. 15

Guardian Structures St. Marys, Ontario (CLT, NLT, mass timber panels) Guardian Structures manufactures glulam, cross-laminated timber, nail-laminated timber, decking, hybrid mass timber panels, and finger joints. With a portfolio of pre-designed homes, multiuse units, and other structures, it also builds customizable mass timber buildings. 16

Sauter Timber Rockwood, Tennessee Established in 2002, Sauter Timber is the first wood component joinery service to set up shop in North America. The organization expanded its offerings in 2010 to include CNC services for mass timber products like CLT and glulam, as well as other timber frame components, SIP panels, and hybrid home and log home components. 17

Nordic Structures Montreal (I-joists, CLT panels, glulam beams) Nordic Structures sustainably manufactures industrial-grade CLT panels, I-joists, and glulam beams. The company has expertise in engineered wood products and mass timber construction with vertical integration from forest to structure. 18

Structure Fusion Saint-Augustin-de-Desmaures, Quebec (glulam, hybrid timber beams, fabrication) Structure Fusion is a Canadian company that specializes in wood construction. Acting as a structural engineer, the company partners with Simonin to design and manufacture adapted wood products, including its patented Sapisol and Resix systems. 19

Bensonwood Walpole, New Hampshire (CLT, NLT, glulam, fabrication) Bensonwood collaborates with architects and engineers to build small and large projects in mass timber and CLT from suppliers like Nordic Structures. A special division uses off-site manufacturing to build timber frames with CNC milling machines that are assembled by hand. 20

Planned Factories Texas CLT Jasper, Tennessee (CLT panels) Texas CLT recently announced plans to open a new plant in southeast Tennessee, near Chattanooga, where it will produce structural CLT. 2

LignaTerra Lincoln, Maine (CLT panels, glulam beams) LignaCLT Maine is LignaTerra’s Northeastern offshoot, which aims to become the state’s first CLT and glulam manufacturer. The company had planned to open a 300,000-square-foot facility in Millinocket, Maine, last year but instead has set its sights on Lincoln. 3

SmartLam North America TBD, Maine In 2018, SmartLam announced plans to open a factory in Maine in hopes of becoming the second producer of CLT in the state, after LignaTerra. The project has been delayed because of funding issues. 4


The Architect’s Newspaper

In spring 2020, designer Jennifer Bonner and engineer Hanif Karif collaborated on a mass timber studio at the Harvard Graduate School of Design. The results of the studio, which was entirely premised on a standard CLT sheet, are collected in a new book, Blank: Speculations on CLT, due out in August from AR+D Publishing.


17 Q&A

Mass Timber Winter 2021


Students in the GSD Mass Timber Studio developed new housing types using only a 9-foot-by-50-foot cross-laminated timber sheet, which Bonner and Kara call a blank.

Architectural designer Jennifer Bonner and engineer Hanif Kara have a beef with mass timber, or, rather, the singular meaning its proponents ascribe to the term. The sustainability benefits of engineered wood products like cross-laminated timber (CLT) have overtaken the discourse around them, the duo finds. Manufacturers have an overwhelming influence on the design of timber buildings, many of which simply substitute structural wood for steel. As they spell out in their forthcoming book, Blank: Speculations on CLT (AR+D Publishing), Bonner and Kara fear that if architects relinquish mass timber to the control of industry, they will miss an opportunity to create a new architecture capable of meeting the exigencies of the 21st century. But Bonner and Kara aren’t dour prognosticators. In the spring of 2020, they organized a mass timber studio at the Harvard Graduate School of Design around a single element, the so-called blank. They instructed their students to use this blank—a structural sheet comprising three- to seven-ply CLT panels that measured 9 feet long and 50 feet wide—toward experimental ends. And the students heartily complied, fashioning trendy villas and topsy-turvy high-rises out of the stuff. These materials are the focus of part of the new book, which also includes speculative essays that explore the blank’s various facets (and the various facets of “blankness”). AN’s executive editor, Samuel Medina, caught up with Bonner and Kara to discuss the project as well as their thoughts on the “complex” building up around mass timber.

18 Q&A

The Architect’s Newspaper


The Architect’s Newspaper: Why did you want to move away from the broad signifier “mass timber” to something as specific as the blank? What discursive trappings of mass timber—or even those of CLT— were you keen to avoid? Jennifer Bonner: “Mass timber” is such a big category. It’s just like saying “concrete.” What we wanted to do instead was to be very narrow in our approach by looking at the CLT blank. And that by limiting ourselves to the blank we would be able to conceptualize and theorize its potential beyond the sustainability narrative that dominates mass timber more generally. Hanif Kara: Without being anti what’s going on [in mass timber], I think that whenever a new material is introduced there is always a “conspiracy” that forms around it with respect to the challenges of the time. When you look at other innovative

materials of the past, what you will see is a rush on the part of certain industry players to direct that material toward one end only. This is the conspiracy, and it effectively excludes nonindustry players and innovators as well as opportunities to intellectualize that material. This has been the situation of mass timber until very recently. Because the challenge of our time is undoubtedly about [building] green, mass timber has been driven toward one end—carbon absorption. Of course, this is a very positive thing. But now that the full [applications and potentials] of mass timber are coming to the fore, we are seeing players of all kinds begin to come out of the woodwork. Excuse the English pun. AN: What was it that drew you to CLT rather than other competing engineered wood products?

HK: When you go to cross-laminated timber, you can see that there is more to it—and more of it—compared to, say, glulam and other things. It also has more credibility than these other [products] do, because it is from juvenile trees and forests. But I had also seen what Jennifer was able to do with CLT at Haus Gables [her 2018 residential project in Atlanta], which AKT II [Kara’s engineering firm] was involved in. As an engineer who has worked with just about every material, I was deeply interested in getting engaged with the way Jennifer’s generation thinks about CLT, which I would describe as being “risky.” Jennifer and I continued to talk after Haus Gables was designed and built. We felt very strongly that we needed to apply a different lens, and that is what we have done with the studio and now the book. By applying this lens—the lens of the blank—we found we could open up a very risky attitude toward design.

JB: Hanif was always saying that there is a danger of losing design to the sustainability narrative. He was always pushing the design questions to the center. HK: Because if you don’t bring these questions to the broader design [community] like the way we talk about it, then engineers and industry will take over. And if that happens, we’ll never really see any architecture out of it. AN: It’s important to underscore that you’re not denying the potential of mass timber to advance an alternative paradigm for construction, even if it isn’t quite the guiltfree paradigm some would make out. HK: Yes, we’re all for it. People are right to connect CLT to the concept of the circular economy, because of its capacity to absorb carbon and be easily recycled. And, as is shown in Norway and Sweden,

19 Q&A

Mass Timber Winter 2021

Facing page: Maggie’s Centre in Leeds, England, makes innovative use of CLT. Kara, whose firm AKT II consulted on the project, praises its curvilinear form, but is quick to note the waste involved in the CNC milling process. Left: Bonner and Kara first collaborated on Haus Gables, a residential home the former designed and built in Atlanta. Kara consulted on the home’s structure, which comprises 87 CLT panels that were hoisted into place by a crane. The experience, while confidence-building, pushed Bonner to speculate on what architectural forms could be generated if the dimensions of a blank remained intact.


it can go hand in hand with sustainable harvesting and manufacturing practices. It can be prefabricated off-site, and because it’s so lightweight it can be quickly assembled on-site. At Haus Gables, for example, the panels were installed in 14 days using cranes. But as your question alludes to, timber just won’t be able to take over the whole market—not in the way some people would like it to. AN: In the interest of better establishing the chronology—it was Haus Gables that drew you to CLT first and then the Harvard studio that pushed you toward the blank. What accounted for that narrowing focus? JB: Hanif and I did Haus Gables a year and a half or so before the studio. With the house, we cut up the blanks into 87 individual panels in order to rationalize the form. In the end, only a few blanks were

used in their entirety. So, thinking about it later, I asked Hanif, “What if we start with the blank first and see what kind of architecture that gets us?” AN: And what kind of architecture is that? JB: For me, the blank pushes you toward procedures of drawing and cutting. Because it’s a sheet material, there is a ready-made quality to the blank. It also collapses, or flattens, architecture and structure—with the blank we get everything in one! There’s also an aesthetics of flatness that comes with it. That’s something [English architect] Sam Jacob explores in his essay in the book. Sam’s whole practice, both the design and theory, has been based on the possibilities of flatness, and even though he hasn’t built with CLT before, he absolutely needs to. It’s totally his material. In my own essay,

I say that Aldo Rossi would’ve loved CLT—like loved it—because he was all about figures, elevations, blankness. But flatness turns into volume quickly, depending on how you put it together, right? There’s just a lot of potential there. AN: That’s an interesting exercise—to read a material back into the history of architecture. You can see that in Ultramoderne’s Chicago Horizon pavilion at the 2015 Chicago Architecture Biennial, the way it translates a Miesian tectonic to mass timber. JB: Totally. Funny that you mention that. Hanif created this diagram of the Maison DomIno that illustrates what the blank does. What’s happening in that diagram is we’re deleting the columns and shoving CLT blanks in between the floors.

HK: With that diagram I wanted to start a conversation about the stereotomic versus the tectonic. It’s that classic geometry question—are you carving space or making space? I also meant it as a challenge to the tropes of modernism that certain architects still hold on to, where the skin is freed from the floorplan. But what if you couldn’t free the skin from the structural system (which is what that Dom-Ino diagram is about)? That’s what we didn’t allow our students so that they would ask themselves how they would rethink their architecture. For us, the availability of the blank absolutely forces us to rethink architecture. Now, the first thing to be said about CLT, structurally, is that it’s not malleable. It can’t be curved easily, because it’s so rigid. It’s not plastic like concrete, which, because it’s so manmade, you can get forensically inside to change its nature. With a blank of CLT, it’s largely a given be-

20 Q&A

The Architect’s Newspaper


Above: Kara put a twist on Le Corbusier’s famous Maison Dom-Ino diagram, removing the point columns and introducing CLT blanks. The diagram demonstrates the many ways the blanks can be configured and cut into while retaining their structural integrity.

Facing page, left: AKT II ran analyses on some of the students’ designs, including Anna Goga’s 300 Panels, 400 Cuts, 400 Bandages.

Facing page, right: For the Blank book, Goga and her peers were asked to rerender their designs against thematic backgrounds.

cause it’s so natural. Of course, as soon as you cross-laminate timber, you have interfered with it in the way we do to steel and concrete all the time. Unlike steel or concrete, CLT is the only material that provides weatherproofing, fire resistance, and insulation in a way. It doesn’t cold bridge, where dampness comes through in cold climates or hot climates. It has truly a unique performative capacity.

fore Wolfsburg the “single surface” would have been something that had surfaces in both directions, where the walls would move on plane. They could rotate from floor to floor. That the blank can do. But it can’t curve in the way Zaha did.

but it also wastes a lot of CLT to show how you can do this kind of curvature. Ultimately, that isn’t what we were studying with the studio.

AN: You’ve just hinted at a few limitations in that description of the blank’s possibilities. What is it the blank can’t do? HK: I genuinely believe that the lack of malleability is an opportunity rather than a problem, and we were able to show that through the studio work. However, something that the blank doesn’t allow for is double curvature. You know, I worked on Zaha Hadid’s Phaeno Science Center [which opened in 2005] in Wolfsburg, Germany. It was probably the height of the “single surface” idea, where wall becomes floor. There is no such thing as a vertical wall in that building. Everything is either a beam or a hybrid between beam and slab. You wouldn’t believe how much timber [formwork] it took to make that concrete. You just wouldn’t believe it. Be-

JB: I guess it really does fail in that way, Hanif. [Laughs.] HK: But the other dimension that is left out is the weight, and that is fundamental. I should do the calculations, but if we had made Haus Gables out of 100-millimeter [4-inch] concrete, it would have probably ended up 10 or 20 times heavier. And you would need metal or timber shutters to form the concrete. You’re right that the blank fails because it can’t achieve what that Zaha project did, but if Zaha Hadid Architects took it on, they could produce something close to that effect using slightly sloped orthogonal blanks. In fact, they are about to start construction on a football stadium in the U.K. entirely made from mass timber. In a way, Thomas Heatherwick’s [2020] Maggie’s Centre [in Leeds, England] is taking that challenge on. It’s one of the projects we have in the book and one that my firm worked on. It is CLT,

AN: You had your students apply the blank toward drastically different ends. Over the course of a single semester, they each designed a single-family house as well as a multifamily, high-rise tower. How did they take to that challenge? JB: We thought it would be an interesting exercise to have them wrestle with the blank at these different scales. Because that’s the phenomenal thing about the blank: its ability to jump scales. As an architect who had done a CLT house—the first time I had ever worked with mass timber—I of course immediately wanted to [next] go as big as I could. I’m not just the house architect, you know? That’s where having Hanif’s support was so valuable. He and AKT II even ran structural analyses on some of the students’ towers. Without him we wouldn’t have been able to pull it off. HK: For the tower, we gave the students a [height] limit based on what we know has already been built; with mass timber

that upper limit is 70 meters [230 feet]. But we also know that, as with all record breaking, the next version will be 10 or 20 percent taller. So that is what we set the students—an increase of 20 percent, but not 200 percent, because that would have been ludicrous. You just can’t do that with CLT yet. But for the height we had specified, the technology is already there. The tower assignment was also related to our thinking about the contemporary urban condition. People all over the world are becoming more urbanized. That doesn’t mean every city will become a Dubai or a New York, but it does mean they will all have a need for higher-density buildings. Over here in Europe, CLT is already being used in social housing, not in supertall projects but what we call “mid-rise” projects. We wanted to expose the students to that typology. And by having the tower-versus-house extreme, we avoided the criticism that always comes from these student housing exercises, where they are doing single[-family] houses for five people. We wanted to stimulate the thinking about the blank and its scalability because we know that the two extremes—and everything in between—are up for grabs now.

21 Q&A

Mass Timber Winter 2021


AN: As with everything else, the studio was impacted by the lockdowns induced by the COVID-19 pandemic. How did the virtual studio setting affect the students’ work? JB: With every studio there’s a ton of representation, and this one was no different. Part of the brief was forefronting animation and simulations of cranes erecting the towers. We had also planned to have these large-scale models in the studio, all of them made out of wood and which everyone would have loved, but then COVID shut us down. So, when we were planning the book, we had the students rerender their towers against different backdrops. Some of them were really flashy and saturated and others were more neutral, like a Yeezy fashion line,

as we put it in the introduction. We also display the “offcuts” of the blanks on the ground, just so that you see how these things are cut up. That’s another kind of representational type we’ve included. AN: That’s interesting, because in your introduction to the book you speculate on the potential for CLT construction to do away with drawing sets altogether. Were you merely being polemical, or is that potential real? JB: I’ve never produced drawings like the “offcuts” we have in the book. Typically, I’d hand my model over to the fabricator or manufacturer, who collapses it and starts running their tooling paths for the CNC machine. There was a moment in the 2000s when everybody was showing


their nested panel diagram and how all their parts fit on a CNC or laser-cutter bed. And we’re aware that these drawings look like those nested drawings, but they’re not. What they’re showing are the blank. There’s nothing nested inside of anything. That’s the full length of the CNC bed. And that these become a kind of figure-ground. But saying that, they are a bit nostalgic because you wouldn’t really ever draw these as an architect. This is all in the machining of the manufacturer now. HK: It’s an interesting thing because for forever architects have connected drawing to making. When you draw concrete and steel, there’s a particular way to draw it that is very detailed and very element driven, but nonetheless it’s abstracted. But when you draw CLT, it is some-

thing like three steps closer to making the building. You are effectively just scaling the drawing up at that point. That is one of the reasons we ran these analyses on the student towers. You can see that if you only made these analyses big enough, you would make the building. You just can’t do that with any other material. What we were trying to show with those stress diagrams was that the material, because it is panelized, allows for redundancy. The real issue, then, is around the joints. Now, there are some people who will say that the connection between drawing and making that the CLT enables is too simple and that in a way we’re going backward. But I like to think that it coordinates itself and, for that reason, we’re moving forward.



Case Study Special Section

The Architect’s Newspaper Mass Timber Winter 2021


The latest timber products demonstrate how advanced applications of this age-old material have become in recent years. Reengineered and reimagined, sustainably sourced wood can be harnessed in everything from interior finishes to skyscraper structures. The following selection of durable flooring, sophisticated cladding, and sturdy framing solutions highlights the dynamism of North America’s expanding timber industry. Innovative fasteners and cutting-edge software specifically for timber construction help the AEC design community find new uses for this material. Case studies show how these materials and tools can be masterfully implemented. By Adrian Madlener

Engineer-Build Structural Engineering

Computational Design

Fabrication & Installation

Beautiful Structures The Soto Office Building | San Antonio, TX Client: Hixon Properties | Design Architect: Lake Flato | Architect of Record: BOKA Powell | General Contractor: Byrne Construction | EOR Concrete Structure: Danysh & Associates Inc. | EOR Timber Structure: StructureCraft



Case Study

Oregon State University College of Forestry

The Architect’s Newspaper


Architect: Michael Green Architecture Engineer: Equilibrium (Katerra) General contractor: Andersen Construction Design assist and build: StructureCraft Manufacturers: Accoya, DR Johnson Wood Innovations, Roseburg Forest Products, Freres Lumber, View Glass, EFCO Within the United States, mass timber is virtually synonymous with the Pacific Northwest, a vast region at whose center lies the Oregon State University (OSU) College of Forestry in Corvallis. The school’s status as a pivotal industry node informed the design of two new building projects—the George W. Peavy Forest Science Center and the A. A. “Red” Emmerson Advanced Wood Products Laboratory—that together form the Oregon Forest Science Complex. Both were designed by Katerra design partner Michael Green Architecture (MGA), and though differing in size and program, both make use of nearly every timber product under the sun, all while setting a high bar for sustainable sourcing and

resilient engineering. At 80,000 square feet, the Peavy Center is the larger, more public-facing of the two structures and houses the College of Forestry’s lecture halls, research laboratories, and a host of administrative functions. These are distributed throughout a pair of simple three-story volumes adjoined perpendicularly at the hip and fastened to the existing Richardson Hall. (The stand-alone Advanced Wood Products Laboratory consists of a lofty structural testing bay, replete with a 25-foot-tall concrete reaction wall and a manufacturing bay.) The college’s mass timber banner is picked up on the building envelope, where off-white bands of acetylated Red Adler blocks—from a patented process developed by Accoya that rot-proofs timber cladding and improves dimensional stability—act as a rainscreen for the stick-built curtain wall system. These vertical bands of wood establish the rhythm for the long facades, while yawning glass curtain walls announce entrances and the double-height atrium. For the roof, the architectural team

opted to use lightweight and durable mass plywood panels developed by Freres Lumber, whose Lyons factory is just an hour’s drive east of OSU. The structural solution is relatively straightforward, shifting between a post-and-beam grid of Douglas fir glulam elements in the common spaces and offices and a hybrid concrete-and-glulam structure in the lecture halls. (Bands of concrete run the length of the horizontal glulam beams where floor spans are greatest, and the two are bonded together with a series of diagonal steel screws.) Crosslaminated timber (CLT) floor plates and shear walls fill out the structural diagram, but the latter disguise a major innovation. Designed by the Portland based firm Equilibrium Engineers and fabricated by Oregon manufacturer DR Johnson, the shear walls are rocking walls, the first to be used in North America. “The concept was originally developed and applied on a smaller-scale building in New Zealand and is in direct response to providing resilient design, given the high seismic

requirements,” said MGA partner Natalie Telewiak. “The CLT shear walls are composed of independent sections connected vertically by a post-tension system. This allows the walls to move and self-center during an event and for components to be selectively replaced on an as-needed basis after the event occurs.” Notably, Peavy Hall, and the greater Forest Science Complex, are constructed of timber products sourced within Oregon. What’s more, the complex is designated a SMART-CLT project and, as such, is embedded with hundreds of sensors that track moisture content, thermal performance, structural movements, and other such indicators to boost the life span of the complex. With the substantial backing of the state’s forestry industry, OSU’s Forest Science Complex has established a template for other universities in the region to follow, whereby campus expansion projects become laboratories for innovation in mass timber design and environmental conservation. This is surely just the beginning. Matthew Marani



Case Study

Mass Timber Winter 2021



Facing page: Douglas fir glulam beams frame the monumental glass curtain wall systems found at the atrium and entrances.

Top: The facade is clad with acetylated Red Adler blocks, which act as a rainscreen for the stickbuilt curtain wall system.

Above: The glass curtain walls and windows use View Dynamic Glass.

Right: The predominant structural system is a grid of post-andbeam-arranged glulam, with CLT filling in as floor panels.




Case Study

The Architect’s Newspaper

A Study in Timber London Timber Pavilion Designer: Schiller Projects Local architect: Novak Hiles Architects Fabricator: Weber Industries Precast concrete table fabrication: Cambridge Architectural Precast Landscaping: Fake Landscapes One morning in July 2020, architectural designer Aaron Schiller was in his New York offices directing a project installation in London. “It was my first-ever FaceTime install,” he said, wincing at mention of the iPhone app. “It was the middle of the pandemic, but I’d really like to avoid anything like it in the future.” He didn’t have to fret for long. The entire process, whereby a crane lifted Schiller’s prefabricated curio off a residential street and up and over a three-story townhouse, gently nestling it on a rooftop terrace, was completed in 20 minutes. Just enough time for a number of onlookers to gather. Schiller could see them only at the corners of his phone screen. “I heard one guy just shout out the word ‘pineapple’ and someone else go, ‘Hedgehog,’” Schiller recalled. The spontaneous epithets—evidence of what he calls “an English tradition of nicknaming buildings”—were good-natured plays on the structure’s bulbous, spiky shell. That shell, actually a porous spherical canopy, comprises dozens of interlocking modules made from standard timber sheets. The thin veneers were laminated with epoxy for strength before being milled into individual shapes identical in form but bearing unique cuts called notches. The curvature of each piece echoes the petal-like contour of the greater canopy itself, reinforcing“the self-supporting logic of the structure that makes it possible for the pavilion to be easily replicated at different scales,” Schiller said. His design practice, Schiller Projects, began by mapping the modules to a sphere while taking into account the head heights of users. The team sent its 3D model to London-based fabricator Weber Industries, which laid it out to the scale of its CNC mill. The laminated, notched “petals” were then steam-pressed over a curved mold. Next, the fabricators fitted the petals together in meridional rows; steel fasteners contribute additional reinforcement in the event of uplift. Once assembled, the quasi dome, accompanied by modular segments of a planter and a curvilinear bench also designed by Schiller Projects, was hauled to the townhouse and craned into place. Timber, because of its light weight, lent itself well to both the brief and installation, but it also exudes a warmth that is particularly welcoming in a city infamous for its rainfall. The canopy, which, thanks to its shape, readily sheds rain, touches down on the bench at few points. Uplights embedded in the bench cast a moody play of shadows befitting a “garden escape in dense London,” Schiller said. While he disavows some of the labels the project has inspired (“We aren’t a parametric design office,” he said), Schiller has come to embrace others. “I never really sat down and gave it a name. But ‘hedgehog’ is pretty good, don’t you think?” Samuel Medina

Top: Schiller Projects developed a fabrication model for the London-based fabricator Weber Industries. The color spectrum indicates how the designers rationalized the pavilion’s form. Middle: The spherical canopy of Schiller Projects’ London Timber Pavilion was prefabricated off-site. Right: It was then hauled over to the client’s three-story row



house. A crane lifted the canopy up and over the house and deposited it on the rooftop terrace. The same process followed for the accompanying furniture pieces—a bench, storage cupboards, a planter—also designed by Schiller Projects. Far right: Uplights embedded in the bench create a moody play of light and shadow on the underside of the canopy.






Mass Timber Winter 2021

Flooring and Decking

Whether fashioned for outdoor or indoor spaces, these engineered planks fit together smoothly and easily. By Adrian Madlener

Wood Tiles Bison Innovative Products

Redwood Decking Humboldt Sawmill

A fixture of Bison Innovative Products’ rooftop decking range, Wood Tiles are a long-lasting and low-maintenance decking option. Produced in ipê, cumaru, massaranduba, garapa, and bamboo variations, this easily and quickly installed product provides warmth and weather resistance to outdoor environments.

Five times stronger than plastic composite products, Humboldt Sawmill’s redwood decking harnesses one of nature’s most robust building materials. Treated to meet Class B flame spread requirements and California’s wildland urban interface fire hazard severity zone standards, this richly textured and grained plank is lightweight and easy to install.

Deck Board Kebony Valour Finish Havwoods Designed for durability, the new Valour Finish by Havwoods is suited for high-impact areas. The engineered floorboards, emulating the look and feel of classic oil-coated floors, come in ten wood tones. As part of the manufacturer’s Venture Planks series, these new variants provide any interior with superior abrasion, scratch, and impact resistance.

Engineered to accommodate four assembly types, the new Deck Board range by Kebony reduces the need for milling and lead time. The Pro Plug system facilitates lateral connections, the Step-Clip is a quick solution that implements install strips, and the Hidden Fastener Clips eliminate the need for additional fasteners. Stainless steel screws can still be used across the Deck Board line.


Hope PID Floors Custom milled for large-scale projects up to 15,000 square feet, PID Floors’ Foundation Line incorporates two-layered engineered planks that combine a European oak top and a Baltic birch hardwood plywood core. Hope is a light, brushed, and micro-beveled variant with a UV-cured finish.




Case Study

The Architect’s Newspaper


Architect: Skylab Location: Hood River, Oregon Contractor: Celilo Construction Civil engineer: Vista GeoEnvironmental Services Structural engineer: VALAR Consulting Engineering MEP engineer: MFIA Electrical engineer: VALAR Consulting Engineering Landscape designer: Shapiro Didway Landscape Architects Lighting designer: Biella Lighting Design Interior designer: Skylab Architecture Windows, doors, and curtain wall: Sierra Pacific SIPs: Big Sky Insulations Glulam: Glenwood Valley Timber Skylab’s new interconnected two-building, 30,000-square-foot complex, named Outpost, is the first mass timber project constructed under new zoning guidelines for Hood River, Oregon’s formerly industrial waterfront. Described by Outpost principal Brent Grubb as “an industrial-size container for workspace,” the mixed-use development is utilitarian but nevertheless makes a visual impact. Skylab inverted a typical mixed-use building organization and stacked retail and offices on top of ground-level light industrial space. The architects reasoned that visitors and tenants would want views of the Columbia River Gorge visible from second-floor open

spaces carved out around an elevator core that serves both buildings. On the third floor, a simple, glulam beam–based structure gives the developers flexibility to break up the open office space with a secondary system if tenants change. The architects chose timber for both economic and aesthetic reasons. Using it for the exposed structure and finishes unifies the project, and the material is humanizing, important in an area that increasingly draws people for work and recreation. “Our goal was to use as much wood as possible,” said Grubb, adding that another rewarding aspect of the project was matching different wood species to appropriate exposures. Locally sourced reclaimed Douglas fir decking was used for exterior flooring. On the facade, clear-sealed cedar clads the double-height ground-floor level, and charred cedar was used on the upper levels. This makes the pedestrian level more approachable and, from a distance, sharply delineates the buildings’ assertive massing and geometry. The design, with its industrial-size operable windows and partially enclosed outdoor common spaces, has proved amenable to pandemic times. And it may be a prescient model for post-COVID times as well. The name of the development, Outpost, comes from the idea that employees may want to live and work where they play, away from an office headquarters. “Our building stands as a prototype for what can happen at the waterfront,” said Grubb. Briana Miller


Top: Clear-sealed vertical ¾-inch tongue and groove vertical cedar cladding with a mix of ebony and vinegar stain treatments is used on the exterior.

Above: Naturally finished cedar cladding delineates the sharp geometry of Outpost, a two-building mixed-use commercial complex. A semi-enclosed space connects the two buildings so that they appear to be part of the same mass.



Case Study

Mass Timber Winter 2021


Top: The building tested new zoning guidelines for the waterfront site with its industrial uses. Left: Skylab’s design lifts complementary retail and office spaces to the second and third floors, above the working double-height industrial space on the ground floor.





Structural Mass Timber

The Architect’s Newspaper

When we talk about timber innovation, we’re talking about mass timber. Between glue-laminated (glulam) beams, dowel-laminated timber (DLT), and cross-laminated timber (CLT), there’s a slew of solutions available to architects, engineers, and contractors tasked with building larger, smarter, and more sustainable structures. By Adrian Madlener

Cross-Laminated Timber Katerra Cross-Laminated Timber DR Johnson

Mass Plywood Panel Freres Lumber

Available in three-, five-, and seven-layer variants, DR Johnson’s cross-laminated timber was the first to receive an APA certification. These 90-degree layered CLT panels are produced using the latest CNC technology.

Freres Lumber’s mass plywood panel uses 20 to 30 percent less wood than standard CLT but with comparable structural integrity. Assembled with Freres structural composite lumber panels, this engineered timber product includes layers of density-graded Douglas fir veneers. Platforms and beams come in thicknesses of up to 24 inches.

Offered in 11 configurations, Katerra’s CLT range comes in three-, five-, seven-, and nine-ply layups. This product is created in the manufacturer’s Spokane, Washington, facility at thicknesses of up to 12.4 inches and lengths of up to 60 feet. Katerra’s CLT is certified by the Sustainable Forestry Initiative, Forest Stewardship Council (FSC), and Programme for the Endorsement of Forest Certification.

Structural Round Timber Columns WholeTrees LIGNIA Fire LIGNIA Sourced from FSC-certified softwoods, LIGNIA Fire has an ASTM E84-20 Class A flame spread rating extended to 30 minutes. The engineered wood’s flame-retardant properties are incorporated on a molecular level and require no additional coating. This material exceeds the durability and aesthetic appeal of tropical hardwoods and provides architects and contractors with a more sustainable solution.

A bountiful by-product of sustainable forestry, unmilled round timber is 50 percent stronger than milled alternatives. WholeTrees’ SRT columns harness this material in 8- to 40-inch variants. These naturally formed, hand-peeled, lathed, or undulating pillars are precut and fabricated with steel connections for quick installation and strong connections.


Glulam Beams Texas Timber Frames Noted for their strength and stiffness, Texas Timber Frames’ glulam beams can span longer distances than comparable products. Prefabricated and CNC-milled for the structures of large-scale public and commercial projects, these lightweight, pressure-formed joists are easily and efficiently assembled.





Mass Timber Winter 2021

These cladding options can transform buildings into textured works of art. Whether made of solid timber or a composite that emulates the durability, longevity, and aesthetic quality of the original material, the following products imbue construction projects large and small with charm while meeting the latest industry requirements and exacting clients’ needs. By Adrian Madlener

Drift Platinum Thermory

Larch Deep Char Pioneer Millworks

Reclaimed driftwood is highly sought after for its soft, ethereal quality but is hard to come by and is often irregularly shaped. Capturing the gray, weathered look of this organically formed material in grooved cladding is the new Drift Platinum by Thermory. Meant for both exterior and indoor paneling, this naturally treated product comes in large C15 profile planks.

In keeping with the tradition of yakisugi fire-finished wood, the new Larch Deep Char cladding from Pioneer Millworks is inherently moisture- and fire-resistant. Engineered to withstand extreme weather conditions, this alligator skin–like siding blackens with time to achieve a cool, dark look while also safeguarding against rot and insect damage.


TandoShake Cape Cod Perfection in Char Tando


Apex Fortress Building Products

Tando’s new Char color option of the TandoShake Cape Cod Perfection line mimics the ever-popular yakisugi technique. Noted for its clean lines and natural cedar textures, this new blackened and burnt iteration is well suited for the modernfarmhouse trend, combining rustic flair with clean lines.

Produced using traditional Japanese charring techniques, the new FSC-certified MATSU range by reSAWN TIMBER features the manufacturer’s signature CHARRED Accoya, a wood variant that retains much more charcoal than softwood species. This versatile indoor and outdoor solution is an option for both dimensionally stable applications and particularly harsh environments.

Suitable for both cladding and decking, the new capped, bamboo-plastic Apex PVC range resembles wood but provides better durability. With nonrepeating grain patterns and an earth-tone color palette, this ecofriendly solution is UV-, fade-, and moisture-resistant.



Case Study

Case Studies in Brief

The Architect’s Newspaper

Karsh Alumni and Visitors Center Architect: Centerbrook Architects Location: Durham, North Carolina Landscape architect: Stephen Stimson Associates Landscape Architects Structural engineer: LHC Structural Engineers MEP/FP engineer: Dewberry

Civil engineer: HDR Contractor: LeChase Construction Services Lighting design: Cline Bettridge Bernstein Lighting Design

The Karsh Alumni and Visitors Center welcomes people to the Duke University campus with a series of warmly lit courts and pavilions that combine new construction techniques with historical motifs. The 48,000-square-foot complex includes various social spaces that comfortably host both large and small groups, including a two-story alumni association office, a meeting pavilion, and the newly renovated Forlines

House, originally designed by Horace Trumbauer, the architect of much of Duke’s campus. Adjacent to the neo-Gothic West Campus, the visitors center reflects Duke’s identity as a “university in the forest.” Exposed wood elements featured across the buildings and a main courtyard complement the locally quarried Duke stone and bird-friendly glass paneling that make up the central pavilion. Keren Dillard PETER A ARON

EF Education First Designer: Gensler Location: Denver Acoustical consultant: K2 Audio Client and collaborator: EF Architecture & Design Studio General contractor: Rand Construction

MEP engineer: Salas O’Brien Structural engineer: KL&A CLT/Timber supplier: Nordic Structures

EF Education First, an international school that specializes in experiential learning, looked to Gensler to create a sustainable office in Denver that would embody the company’s ethos and the spirit of Colorado. The resulting CLT structure echoes the look and feel of the neighboring Rocky Mountains, connecting visitors to the great outdoors through natural colors, textures, and materials. High ceilings, natural light, and exposed timber beams create airy interiors. The biophilic

color palette of the spaces—including soft tones and warm woods—mimics the surrounding landscape. A minimal reception desk, molded out of rammed earth from local soil, nods to Colorado’s red rock canyons, and a stairway with rows of floor-to-ceiling pine boards conjures the feeling of hiking through a forest. Adjacent lounges and workspaces are flanked by movable timber walls that allow team members to alter spaces depending on their needs. Ali Oriaku


Hotel Magdalena Architect: Lake | Flato Architects Location: Austin, Texas Client and interior designer: Bunkhouse Group, Tenaya Hills Timber superstructure structural engineer: StructureCraft Base building steel and concrete structural engineer: Architectural Engineers Collaborative MEP engineer: Integral Group Landscape architect: Ten Eyck Landscape Architects

General contractor: MYCON General Contractors Dowel-laminated timber panels: StructureCraft Windows and doors: Sierra Pacific Aluminum Clad Wood Windows/Doors, La Cantina Aluminum Doors, EFCO 5600 Slimline Aluminum Storefront

Hotel Magdalena is the first mass timber boutique hotel in North America. This 100,000-square-foot oasis honors the former site of the Austin Terrace Motel in Austin, Texas. Hotel Magdalena welcomes its visitors with a two-way gridded porte cochere and hosts a series of vibrant common exterior spaces, outdoor walkways, shaded porches, and lushly planted terraces that recall lake houses and natural arte-

sian springs found in the Texas Hill Country. The exposed wood in every space provides a warm and textured ambience that ensures the timber structural components are an integral part of the hotel experience. This is also meant to spur daily conversations about sustainable construction and building practices. Keren Dillard CASE Y DUNN



Case Study

Mass Timber Winter 2021

Great Notion Brewing Firm: ZGF Location: Portland, Oregon Developer: OSB2LAN MGM Fire protection engineer: Wyatt Fire Protection General contractor: Centrex Construction Structural engineer: KPFF Consulting Engineers

Timber installer: Carpentry Plus Timber suppliers: DR Johnson Lumber, Nakamoto Forestry

A former warehouse in Northwest Portland, Oregon, has been transformed into the home of Great Notion Brewing, whose state-of-the-art taproom, coffee shop, and office space enliven the industrial neighborhood. Designed by ZGF, the building uses modern timber technology and locally harvested materials to showcase the region’s manufacturing roots. The repurposed taproom, constructed of

cross-laminated timber (CLT) and clad in naturally weathering Cor-ten steel panels, is connected to a spacious lobby made of yakisugi Japanese burnt timber. The raw CLT panels contrast with the black charred wood entry to create a bright, warm, and inviting space where patrons can drink Great Notion’s beers and marvel at the massive metal fermentation tanks that sit behind a nearby glass wall. Ali Oriaku PETE ECKERT

SoLo Architect: Perkins&Will Location: Soo Valley, British Columbia Client: Delta Land Development Electrical engineer: Rainbow Electric Energy consultants: Gencell, VREC Fire protection engineer: Viking Fire Protection General contractor: Durfeld Builders

Glazing: Blackcomb Glass HVAC: Custom Air Structural engineer: StructureCraft Timber supplier: Structurelam Welder: OpenWide Welding Windows: Optiwin

Overlooking the Soo Valley in British Columbia’s Coast Mountains, SoLo, designed by Perkins&Will, is a Passive House–certified home made almost entirely of Douglas fir. Perkins&Will transformed the remote site into a luxury off-grid retreat that produces more energy than it consumes, with combustion and fossil fuels removed from its daily operations. The project’s strategically limited material palette reduces the home’s embodied carbon footprint. The modular, prefabricated timber

panels were trucked to the site and lifted into place by crane, reducing waste and construction time. Because of the valley’s harsh climate, the enclosure is composed of two layers of timber, with a heavy outer frame serving as a weather shield, and an insulated inner layer designed to contain heat. A glass curtain wall found at the rear of the home lets guests take in a view of the valley. Ali Oriaku ANDREW L ATREILLE

Kendeda Building for Innovative Sustainable Design Design architect: The Miller Hull Partnership Collaborating architect and prime architect: Lord Aeck Sargent Location: Atlanta Timber installer/framer: Universal Timber Structures Timber supplier: Unadilla Laminated Products Salvaged lumber finishes supplier: Raydeo Enterprises General contractor: Skanska Landscape architect: Andropogon The Kendeda Building for Innovative Sustainable Design is the first mass timber building on the Georgia Institute of Technology’s campus, and its 46,848 square feet of programmed space makes it the largest higher education building to achieve Living Building certification.

Design engineer: PAE Electrical engineer: Newcomb & Boyd Civil engineer: Long Engineering Structural engineer: Uzun + Case Graywater systems water consultant: Biohabitats

It uses FSC-certified, responsibly harvested timber for its decking, benches, tables, and counters. According to the architects, that has saved 33 percent more carbon from being released than if the wood had come from a non–sustainably sourced supplier. The architects

also said that the wood in the project has sequestered more than 100,00 kilograms of carbon dioxide. The Kendeda Building embodies a bold, values-driven vision that promotes sustainable construction and design methods. Keren Dillard





The Architect’s Newspaper

Timber Construction Software

The latest software and building-information management tools help architects, engineers, and contractors achieve accuracy and maintain control, especially when dealing with a myriad of components at once. Optimized for timber construction, these programs facilitate wall and floor framing, product specification, and more. By Adrian Madlener


Stellar Weyerhaeuser


Framer SketchUp

Stellar is inventory software by Weyerhaeuser that assists dealers and specifiers in making decisions when ordering lumber. In addition to keeping track of orders, the program generates optimized shipping lists and instructions for automated cutting equipment.

RISA-3D is an easy-to-use program that connects geometric visualizations with input spreadsheets. Its dynamic-analysis feature allows architects and engineers to rapidly design wooden structures. The software can also create clear, visually appealing reports.

SketchUp offers its users a wide range of design and construction-related extensions. Recently launched by third-party developer John Brock, a custom-home builder, the Framer plug-in can imbue almost any SketchUp model with accurate and realistic timber frames.

Shearwalls 2019 WoodWorks

BC FloorValue Boise Cascade

GSE Wood Safi

Capable of modeling wood frame structures up to six stories tall, WoodWorks’ Shearwalls 2019 software conforms to NDS 2018, IBC 2018, ASCE 7-16, and SDPWS 2015 standards. Certain functions expedite the treatment of wind and seismic loads. The program simulates load distribution and generates shear walls.

BC FloorValue was developed by Boise Cascade to complement the company’s suite of engineered wood products. The software identifies issues within floor designs before installation by detecting areas of weakness, poor weight distribution, sheathing deflection, or excessive vibration.

Developed by Safi, GSE Wood is a general-structural engineering software program made for designing and analyzing engineered wood beam-column structures and light wood framing. A suite of extensions provides architects and contractors with the possibility of combining these two types of construction and working with automated parametric generation.




Mass Timber Winter 2021

Ties and Fasteners

It is easy to take the screws that hold timber structures together for granted, but the right ties and fasteners can make a world of difference. The smallest variation or detail can have a significant impact when these items are used in large projects. The following products can enhance builders’ flexibility, accuracy, and speed. By Adrian Madlener OlyLog FastenMaster The innovative, sleek, and slender OlyLog structural log-home fastener by FastenMaster requires no predrilling, which significantly cuts down on construction time. A welcome alternative to lags and spikes, this new removable and reusable screw countersinks into timber logs, allowing the material to settle naturally.

ConnexTite HT full thread SFS Intec The ConnexTite HT full-thread fastener by SFS Intec is engineered for precision connections and sturdy reinforcements. Its full-thread, point and shank profile is optimal for the transfer of high tensile and compressive loads regardless of the timber’s properties.

Deck Screws Conquest With a larger surface area and sharper threading than the industry standard, Conquest’s Deck Screws are easy to secure, and they create strong bonds. Engineered specifically for decking, the fastener is made of corrosion-resistant steel and comes in 304 and 316 sizes as well as flat head and trim head variants.


KKT COLOR Rothoblaas

SawTec Eurotec

The cone-shaped and concealable KKT COLOR head screw by Rothoblaas is designed for the outdoor installation of wood and WPC boards. An anticorrosion coating ensures this carbon steel fastener’s longevity, while its various colorways make for a close-to-seamless pairing with many types of wood.

Noted for its two-stage cylinder head, the SawTec screw by Eurotec features a unique geometry that reduces screw-in torque and avoids splitting. The hardened carbon-steel tie is electrogalvanized for use in service classes 1 and 2. A TX drive keeps the SawTec from being knocked over when being screwed in.

Strong-Drive WSV Subfloor screw Simpson Strong-Tie

Recently approved for use with fire-retardant lumber, Simpson Strong-Tie’s Strong-Drive WSV Subfloor screw has a tip and thread pattern that provides easy starts. The yellow zinc–coated tie’s aggressive variable-thread profile cuts down on driving force and speeds up installation.



Resources Cladding Accoya Fortress Building Products Pioneer Millworks reSAWN TIMBER Tando Thermory

Flooring and Decking Bison Innovative Products Havwoods

Humboldt Sawmill Kebony PID Floors

Software Boise Cascade RISA Safi SketchUp Weyerhaeuser WoodWorks


The Architect’s Newspaper

Ties and Fasteners Conquest Eurotec FastenMaster Rothoblaas SFS Intec Simpson Strong-Tie

Katerra LIGNIA Raydeo Skanska StructureCraft Texas Timber Frames WholeTrees Unadilla Laminated Products

Timber DR Johnson Freres Lumber


UPCOMING VIRTUAL WORKSHOPS Our CE|Strong workshops are curated according to region within the Continental United States. On-hand instructors will respond to the application of their materials and software tools to local conditions: such as proper insulation to avoid thermal bridging in regions prone to harsh winters and efficient UV protection for glazed facades. Attendees will leave with a greater understanding of efficient material uses which blend with overall design approaches.

Northeast April 14

Southeast June 30

Pacific Northwest Southwest May 19

July 21



June 16

August 18

To register go to

38 Comment

The Architect’s Newspaper

There’s More to Timber Building than Trees Designers would benefit from a larger, nonlinear perspective on what exactly mass timber is and does at the scales of the building and forests. There is a prevailing sense among proponents of mass timber that building with wood is inherently good. This enthusiasm is largely premised on a key assumption that if a tree sequesters carbon as it grows, then mass timber building components must count as stored carbon. But if the source of that wood—a forest— is a source of carbon emissions, as is beginning to happen in Canada, for instance, due to drastically changing climates, then any material extracted from that source cannot magically and suddenly become a carbon sink. This is all the more true when a mass timber building component has been extracted, transported, processed, installed, maintained, and eventually demolished through carbon emission–intensive processes. Even if the timber destined for, say, cross-laminated timber (CLT) panels is extracted from a carbon-sink forest, the amount of stored carbon extracted from that forest can be quickly matched, and likely exceeded, by the amount emitted in subsequent production and transportation processes. Or to state the matter in other terms, just because you have a debit card does not mean you have any funds in your account. To extract, and count, the stored carbon in mass timber building components as independent of both the forest and all the other terrestrial processes that engender that mass timber building component will only exacerbate—rather than ameliorate—carbon emission–based environmental problems that drive our changing climates. Our ability to properly reason about and imagine the carbon dynamics of mass timber building hinges on our ability to expand our understanding of timber to include forests. Wood comes from forests, not just trees. Trees are but one part of a forest’s larger ecology and carbon cycle. To properly understand, and thus design, a mass timber building requires designers to begin to see the forest for the tree (assuming they even see the tree for the mass timber building component). Consider, for instance, the respective forests of New England and Quebec. The boreal forests of Quebec are very extensive black spruce stands, often held in very large ownership tracts, all in the resource extraction-intensive context of the Canadian economy. This singular species, its specific material properties, and the socio-economic context of the relevant forestry practices together suit the production of CLT panels quite well. By contrast, New England presents a very different forest. Much smaller stands of mixed hardwood species, along with a coniferous mix changing with the changing climates, characterize New England woods. Furthermore, much of the New England forest is held by a plethora of small land owners who often retain a misguided conservation ethic in which trees are never cut, at the expense of forest health, biodiversity, water quality, and resilience. In the New England context, and by extension the New York City context, CLT panels are not at all obvious as a forest product for the building industry. That is, at least in part, because smaller mass timber components, made in smaller and more diverse facilities and from a more diverse mix of species and harvesting practices, suit the forests of the northeastern states. Such observations about the specificity of forests are merely emblematic of how architects might begin to design not just mass


Students of the author developed this GIS-generated map of New England forest types.

timber buildings and their carbon dynamics but, even better, the reciprocities of mass timber building and forest building. The ultimate merits, or environmental and social burdens, of timber building will come to bear not only on the performance of a particular building but on that building’s contributions to the dynamics of its forests. This inherent reciprocity must be researched and designed as much as the building itself. For instance, in aesthetic and formal terms, if a conventionally “beautiful” mass timber building is the result of vulgar forestry practices and material geographies, then it becomes less architecturally satisfying. Or, likewise, if a mass timber building’s shallow claims of carbon neutrality based on a life cycle assessment (LCA) serve only to mask ill-considered forestry dynamics, the final merits of its architecture—carbon and otherwise—are cast into doubt. In methodological terms, an LCA of timber building components does not account for the forests’ biogeophysical energy, material, and information. Instead, LCA studies begin only after extraction has taken place.

In other words, in the case of mass timber components, life cycle assessments paradoxically occlude the living portion of the tree and forest dynamics that do the sublime work of photosynthesis and carbon sequestration, to say nothing of the related cycling of water, biodiversity, and respiration. This imponderable occlusion makes meaningful LCA-based carbon claims dubious at best, for all the key carbon sequestration processes occur in the time and space of biogeophysical forest growth, which LCAs omit from consideration. Whether in terms of design or research, addressing this blind spot entails not expanding LCA accounts of building products, but finally engaging ecology-based descriptions of the complex forest–tree-factory–building carbon dynamics. We need, in short, design and research methods that see the forest for the mass timber building. To adequately consider mass timber building, then, is to rethink the systems and boundaries of conventional construction. Designers would benefit from a larger, nonlinear perspective—a more inclusive system-

boundary definition—of what exactly mass timber is and does at the scales of the building and forests. In such a definition, mass timber buildings are another type of carbon pool in the carbon cycles of a forest; a cache of carbon like that buried in forest soil or woody litter on the forest floor. In this regard, mass timber building, like any type of construction, is a territorial proposition. It is also a unique molecular proposition. Architectural design based on the unique molecular properties of mass timber has important implications. For example, engineer Salmaan Craig is currently refining an approach to uninsulated, single-layer solid mass timber buildings that matches Passivhaus standards. Structure, enclosure, what architects call insulation, and finish materials—all in one radically integrated conception of mass timber. In Craig’s approach calibrated holes in the mass timber wall turn the structural panel into a heat exchanger. Interior heat conduction moving through the solid mass timber heats incoming, buoyancy-driven ventilation air. The approach eliminates not just insulation but also mechanical heat exchangers and other equipment. Relieving future genres of buildings of carbon-intensive, randomly sourced layers of construction and mechanical systems goes a long way toward engendering positive environmental impacts through design. Much like the unique properties of a forest, mass timber building today involves deep forays into the unique properties—and potentials—of mass timber material components as well. From the territorial to the molecular, architects, engineers, and foresters are—together—beginning to re-engage the fundamental terrestrial character of mass timber building. They are beginning to see the forest for the building and vice versa. They are also beginning to peer into novel molecular architectures as they pioneer a new paradigm of carbon-positive building. The upside of recent mass timber building interest is that architects in particular are beginning to unlearn what modernity trained them to forget: that to understand building—both as a noun and as a verb, as components and processes—is to understand the full range of ecological, social and political relations that engender building as a broad terrestrial process. When compared with steel and concrete, mass timber could trigger evolutionary change, a paradigm shift toward a much more ecologically sane approach to construction. But this new paradigm will not emerge from merely substituting one material for another. It is, rather, the result of a change in how designers think about building as a terrestrial process at a range of scales—that is to say, its actual ecology, its thermodynamic potentials, and its socio-economic bonds. It is a result of thinking through the construction ecology of building, with the aim not of doing less bad by minimizing environmental impacts but rather maximizing the good that design can achieve at a range of scales, through the design of building as an inherently terrestrial act. Kiel Moe is a practicing architect and the Gerald Sheff Chair in Architecture at McGill University. He is the author of many books, most recently Unless: The Seagram Building Construction Ecology, out now from Actar.



40 Pictorial

The Architect’s Newspaper

Timber on Tour

NADAAA reinterprets the structural bones of Venice in a pair of CLT projects for this year’s Biennale. The Venice Architecture Biennale is architecture’s most esteemed platform. It’s where architects from around the world gather to display their latest research, be it material, typological, or theoretical in nature. For Nader Tehrani, whose Boston-based architecture and urban design firm, NADAAA, is a participant at this year’s Biennale (opening May 22), the challenge lies in combining all three strands. NADAAA developed two installations for Venice: one for a portico positioned at the terminus of the Arsenale, the primary exhibition hall of the Biennale, and the other a housing prototype located within it. Both projects suss out the possibilities of cross-laminated timber (CLT), but for “totally arbitrary reasons,” Tehrani said. Perhaps not entirely. In recent years, NADAAA has implemented CLT in a handful of projects, including the North Hall dormitory at the Rhode Island School of Design, which opened in late 2019. And then there is the bare fact of Venice’s construction, a stone city held aloft above a lagoon by wooden piles. “Part of the desire was to make visible that invisible infrastructure, even while acknowledging that CLT is a different technology and a different way of using it,” Tehrani said. He clarified that the Venice installations pursue opposing trajectories for CLT and, for that reason, should be taken together as a complementary pair. As Tehrani explained, whereas the portico is “a one-off that radicalizes, let’s say, the ‘figure’ of architecture,” its counterpart “suppresses it to instead explore how something as standard as a CLT panel can become the basis for mass customization.” It’s true that the zigzagging portico, pictured here, cuts a compelling figure, with a herringbone pattern that suggests the process of laminating sheets of timber to create CLT. It also serves as a shelter for a vaporetto stand, if a rather glamorous one. That is to say, it’s perfectly at home in Venice.


Top: A perspective view of a portico the Boston-based architecture firm NADAAA designed for the Venice Architecture Biennale. Right: The portico is one of two CLT-related projects NADAAA will unveil at the event.

Far right: A herringbone pattern on the inner and outer surfaces of the canopy alludes to the stacking-and-lamination process by which CLT is produced.



Upcoming Events in 2021 Breaking the Georgian Mold (VIRTUAL)

Boston (1-DAY)

Great Lakes (VIRTUAL)

November 4+5

June 24 July 15

October 26

Los Angles (2-DAY) Canada (VIRTUAL)

November 11 Building Performance in the Lone Star State (VIRTUAL) Seattle (1-DAY) July 22

2-DAY HYBRID) HYBRID) New York City (2-DAY

August 5+6

Portland (AM) September 15

Washington DC (AM) September 21

Denver (1-DAY) September 30

Chicago (1-DAY) October 8

Follow for upcoming event schedules

December 3

Virtual Harnessing Technology for Future Practice May 20, 2021 After a turbulent year of adjusting forecasts and changing expectations, 2021 will be a year of reemergence and growth for the AEC industry. While construction may be known for more traditional approaches that have stood the test of time, many practices have emerged that have allowed for improved communication, more complex digital fabrication, and striving innovation in the face of safety concerns and a competitive market. Tech+ Virtual Harnessing Technology for Future Practice will showcase the latest tools and research relevant to architects, engineers, and construction practices from leaders who are quantifying physical properties within the digital environment.

Register at

Sponsorships: Diana Darling | 212 966 0630