If the steady stream of newly announced mass wood projects is any indication, mass timber building technologies are poised to take the American construction and design industries by storm over the next few years. As products like cross-laminated timber (CLT), nail-laminated timber (NLT), glue-laminated timber (glulam), and dowel-laminated timber (DLT) begin to make their way into widespread use, designers, engineers, and builders alike are searching for the best—and sometimes, most extreme—applications for mass timber technologies. But rather than reinvent the wheel, American designers can look to experienced mass timber designers in Europe and Canada for key lessons as they begin to test the limits of these materials in the United States.

European and Canadian architects and researchers have long been at the forefront of mass timber design, starting with early experiments in the 1970s. By the 1990s, researchers like Julius K. Natterer at the Federal Institute of Technology in Lausanne, Switzerland, were developing initial CLT prototypes. Natterer’s work has been buttressed by that of many others, including research performed at the Norwegian Institute of Wood Technology under Thomas Orskaug and experiments conducted at the Technical University of Munich under Stefan Winter.

One key lesson European timber projects teach is that when it comes to structural systems, weight matters. On average, mass timber assemblies weigh between one-third and one-fifth as much as concrete structures, despite equivalent structural capacities. As a result, mass timber buildings are much lighter than concrete ones, a positive for building in tricky urban situations, for example—where underground rail yards, subway tunnels, and municipal utilities place limits on how heavy and tall buildings can be.

London-based Waugh Thistleton Architects (WTA), for example, recently completed work on Dalston Lane, a 121-unit CLT midrise complex located above a tunnel serving the Eurostar train line in the city’s Hackney neighborhood.

For the project, the architects worked with timber-engineering specialists Ramboll to develop a stepped tower cluster rising between five and ten stories tall. CLT panels are used for the external, party, and core walls of the building, as well as the stairs and the building’s floors. The variegated massing is due directly to the architect’s use of CLT construction, which resulted in a lighter building that allowed the designers to build taller without more extensive foundations. The resulting building, with its staggered massing, better maximizes daylight infiltration into apartment units. The added height allowed the architects to add 50 more units to the project than originally permitted, a testament to just how light CLT can be.

From The Architects Newspaper: archpaper.com