Those of you who know me, even a little bit, know about my passion for mass timber buildings. I mean, who wouldn’t? They’re beautiful, innovative, new technology, cost competitive, and a green alternative to steel and concrete framed buildings. Did I mention they’re beautiful? As a structural engineer, I was first drawn to this material a decade ago due to its strength and minimal wood shrinkage/dimensional stability.

Before I get too far ahead of myself, I guess I should define mass timber building for those playing catch-up. Otherwise known as heavy timber, these wood buildings utilize products like cross laminated timber (CLT), nail laminated timber (NLT) and glulaminated timber (glulam).

Buildings like what we designed at Redstone Arsenal or Fort Drum, the first and second CLT framed hotels in the country.
And even the roof of the Buffalo HarborCenter that we designed with Nordic Structures.

We’re seeing mass timber currently utilized where it is shown off for its beauty. We also see it in markets where the cost of labor is high and speed of construction is critical. Since all the structural material is fabricated offsite, there can be significant savings in time of construction and reduction in labor cost. On our Redstone Arsenal project, the hotel was constructed 20% faster (three months) and with 44% less man hours for a similar light-gage framed hotel. With the soon to be adopted code changes, we have greater opportunity to use it in new ways.

What’s next:

  • Did you know that we’re seeing mass timber buildings pop up across North America at an exponential rate?
  • Did you know that mass timber buildings are likely to continue to grow exponentially for the foreseeable future?
  • Did you know that the 2021 International Building Code has already been finalized and includes changes to expand Type IV construction (mass timber) to up to 18 stories tall?

Yes, you heard that right, 18 STORIES!!! In fact, you can already find high-rise mass timber buildings (complete/nearing completion) across the world that stand 18 and 24 stories. The United States is finally catching up to the rest of the world in this exciting industry!

So what code changes am I talking about? Our friends at WoodWorks have a nice, tidy white paper on the finalized code changes. In summary, Type IV construction will be split into four different categories: Type IV-HT, Type IV-A, Type IV-B and Type IV-C. The different categories allow for differing amounts of exposed wood and differing fire rating requirements, along with corresponding height and area restrictions. Type IV construction can be utilized for Mid-Rise, Mixed Use, Residential Housing, Hospitality, Office or even Industrial applications.

So why is this such a big deal? Typically, the most economical buildings five stories and under are stick-built wood construction. Most owners scratch their heads when they want to build taller. Mass timber is meant to compete with steel and concrete construction and now owners have more options. My opinion is that the sweet spot for this construction type is 6-10 stories tall.

If you are feeling like you are playing catch-up on this topic, don’t worry, we have your back! We’ve seen the potential and are leading the field in the mass timber industry.
We’ve been involved in 20+ mass timber buildings over the past five years.
We’ve educated audiences across the country on the topic and would love the opportunity to bend your ear.
While a mass timber building is by no means the right solution for every project, the soon to be adopted (and already adopted in Oregon, Washington and California) code changes make what our Schaefer team has known for years as a reality: mass timber is a great alternative building owners should consider.



  • Hello, Doug

    Very interesting and well written article on the use of structural lumber for increasingly larger and taller structures. Great to see engineers continuing to develop innovative uses for one of the worlds oldest building products.

  • DOUG,

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