That’s slowly changing. Oregon recently approved an addendum to its building code that allows timber structures to be built over six stories without having to acquire special permission. This update to the state’s buildings code comes after years of scientific and technical evaluation around technologies like cross laminated timber, and it effectively recognizes mass timber as a safe and viable mode of construction going forward.
The state splits mass timber into three new classifications—buildings over 18 stories (270 feet), buildings with a maximum height of 12 stories (or 180 feet), and buildings that rise nine stories (or 85 feet). All three classifications have different requirements, with the tallest buildings being required to enclose all exposed timber surfaces and pass a three-hour fire-resistance rating for its structural pieces. At lower heights, the buildings can expose their lovely timber bones.
As architects dream up of more timber high rises, Oregon’s new regulation could guide other states flirting with mass timber to embrace the material.