The exceptional strength and efficiency of mass timber construction has been well documented for generations. A look around any American city will show mass timber buildings that have been used safely, in some cases, for hundreds of years.
Massive wood structural elements, combined with solid wood floor assemblies, create structures that are strong, resilient and efficient, both in how space is designed and how energy is used. The unique fire resistance of mass timber components is also well documented, but less well understood.
Extensive fire testing prior to approval of the 2015 International Building Code and recent 2017 fire resistance testing by the federal ATF Fire Research Laboratory and USDA Forest Products Lab has confirmed the inherent fire resistance of mass timber buildings. Mass timber is fundamentally different from dimension lumber; mass timber elements resists fire as exterior charring insulates the structural integrity of the underlying component.
Mass timber elements include Cross Laminated Timber (CLT), Nail Laminated Timber (NLT), Dowel Laminated Timber (DLT) and Glued Laminated Timber (Glulam). Each of these mass timber technologies, has distinct benefits as a building material:
- The resilience of mass timber panels offers the strength of steel with lower weight. The superior strength-to-weight ratio offers design options and cost advantages;
- Mass timber is a renewable resource that sequesters greenhouse gasses and is manufactured at much lower energy intensity than other materials;
- Mass timber buildings offer design options and precise building envelopes that significantly reduce energy consumption;
- Mass timber panels and components can be installed by a wide labor force, more easily and in less time than other construction methods. This reduces costs, eases dislocations during construction and helps with industry labor shortages;
- The design flexibility afforded by mass timber offers the option of creating more desirable and efficient built environments than tradition reliance on steel and concrete. New mass timber buildings are among the most innovative structures in the world.
Tall Mass Timber Buildings are growing in popularity because of their strength, resilience and efficiency. These mass timber buildings are also cost effective and have been built with less disturbance to the surrounding community because of the ease and speed of construction using mass timber components. These buildings are examples of Tall Mass Timber Buildings (TMTB) approved by local officials and built under local codes. The ICC Ad Hoc Committee on Tall Wood Buildings has made proposals to ensure that the IBC remains relevant and provides local officials with the tools they need to ensure future mass timber buildings meet the highest standards.
Carbon 12, United States
(Credit: carbon12pdx.com) Carbon12 is a luxury condo building in Portland, OR that is currently the tallest mass timber building in the United States. Completed in 2017, Carbon12 was built with cross-laminated timber (CLT) and stands 85 feet tall.
Brock Commons, Canada
(Credit: Brudder, naturallywood.com) Brock Commons, a student residence building at the University of British Columbia in Vancouver, is currently the tallest mass timber building in the world. Brock Commons was completed in 2017 and stands 174 feet tall.
T3, United States
(Credit: Ema Peter/MGA) Completed in 2016, T3 (timber, technology, transportation) is a mixed office and retail building in Minneapolis, Minnesota. T3 was built with nail-laminated timber (NLT) and is 7 stories tall.
(Credit: Sweco/Artec) Treet is a luxury apartment building located in Bergen, Norway, completed in 2015. Built with mass timber glulam columns and CLT walls, Treet was completed in 2015 and stands 160 feet tall.
Wenlock Cross, United Kingdom
(Credit: Hawkins Brown) Wenlock Cross is an apartment building completed in 2015 in London, UK. Wenlock Cross was built with a CLT hybrid structure and is 10 stories tall.
(Credit: Mikko Auerniitty) Puukuokka is an apartment complex comprised of three 6-8 story buildings in Kuokkala, Finland. It was built using CLT and was completed in 2015.
Wood Innovation Design Centre, Canada
(Credit: MGA) The Wood Innovation and Design Centre located in Prince George, British Columbia serves as a hub for the development of innovative uses of wood, and houses academic, government, and industry tenants. The WIDC was built with CLT floor panels and glulam columns, and was the tallest modern all-timber building at 97 feet tall at the its completion time.
Cenni di Cambiamento
(Credit: European CEO) Cenni di Cambiamento is a social housing apartment complex located in Milan, Italy. Completed in 2013, the complex is composed of four 9 story towers and 2 story connector buildings made with CLT panels.
(Credit: Keith Webb) Located in Melbourne, Australia, Forte is a 10 story apartment building completed in 2012. The tower was the first Australian building made with CLT and is 106 feet tall.
LifeCycle Tower ONE, Austria
(Credit: CREE Buildings) The LifeCycle Tower ONE is an office building located in Dornbirn, Austria, that was completed in 2012. Primarily made of glulam wood beams, LifeCycle Tower ONE is 89 feet tall and was erected within eight days of the foundation being finished.