The choice of construction materials, no matter the size of a project, can create a measurable environmental impact. In the previous blog we discussed the significant attributes of Cross Laminated Timber or MASS TIMBER construction as compared to common steel and concrete for mid-rise buildings. We showed how all wood construction is faster, weighs less, and sequesters carbon as compared to steel and concrete buildings.

So, if CLT really is a more sustainable material, why isn’t it more commonly used in the U.S?

Photo courteous of APA-The Engineered Wood Association

Europe has seen quite a few multiple-story CLT buildings, along with Canada and slowly the US, with more being built.

Europe and Australia:

    • Norway: Treet Building 14 stories
    • UK: Trafalgar Square 10 stories
    • UK: Banyan Wharf 10 stories
    • Australia: Forte 10 stories

Canada:

  • T3 Minneapolis: 7 story 220,000 sq ft., lumber came from beetle kill fir trees
  • Brock Commons: 18 stories

United States:

    • Design Building at University of Massachusetts in Amherst
    • University of Arkansas: 5 story dorms 200,000 sq ft. 368 rooms with construction materials sourced from local Arkansas forests. 
    • Portland: Carbon12, 8 stories, 42,000 sq ft 

Photo Courteous of Carbon12pdx.com

With more being built and projected plans for additional structures in Austria and Australia, why have we not seen more of this construction in the U.S?

Two reasons: Restrictive building codes that are now just studying CLT and reluctance of manufacturing facilities to produce laminated panels. However, changes are beginning to take effect as demand for this type of construction increases and awareness of its various benefits. 

Let’s consider carbon emissions. A 2009 study by engineering researchers at the University of Canterbury in NZ found the following:

  • Mid-rise construction for steel and concrete buildings produces 1500 tons of net CO2.
  • Mass timber construction by comparison releases only 610 tons of CO2 stored in wood.
  • The Brock Commons building in Vancouver Canada claims it will become Carbon Neutral in 12 years.

With forests being one of America’s greatest natural resources, is using mass quantities of wood sustainable? In short, yes. The trees needed for CLT mills grow fast. The United States Department of Agriculture states net growth of timber in America in past years was 26.4 million cubic feet while the forests removed were 12.8 million cubic feet, close to half! CLT mills prefer small diameter logs of only 10” average girth which allows these trees to be cut earlier and replenish quickly. 

Another benefit that often goes unmentioned is the projected employment growth CLT mills and harvesting would result in. In Europe, the bulk of the timber supply has come from Austria. The United States is blessed with a greater acreage of forests; consider Washington, Oregon, and Northern California. The industry will need many people in selective logging, new saw mills and CNC manufacturing mills in these areas. 

As a knowledgeable Owner’s Representative, it is my moral responsibility to influence the use of environmentally sound practices over traditional carbon intensive practices. As a whole, project managers in construction can create monumental environmental changes by influencing developers and design teams to adopt these practices.

With the use of CLT materials in construction, we can create a construction process that is quicker, less wasteful, and less disruptive to the neighborhood.

I invite you to book a free exploratory consultation to discover what sustainable practices your design team can incorporate into your current or future neighborhood project.