The state of Utah and the city of Denver, Colorado, have taken the lead in introducing mass timber into its Building Code, as of 2020. Mass timber is defined as the use of large, solid wood panels for wall, floor and roof construction. New specifications for mass timber fire safety are included in the 2021 IBC (International Building Code), with different specifications for buildings of over 9, 12 or 18 stories, ranging from gypsum board covering of mass timber up to a two hour fire resistance requirement. The move by Denver was welcomed by the American Wood Council (AWC).
“Denver adopts tall mass timber codes”, 7th January 2020 https://www.constructionspecifier.com/denver-adopts-tall-mass-timber-codes/
“AWC Commends Legislation on Tall Mass Timber” (Utah) 27th March 2019 https://news.thomasnet.com/companystory/awc-commends-legislation-on-tall-mass-timber-40022759
AWC summary on “Tall Mass Timber” https://awc.org/tallmasstimber
reThink Wood brochure on “Mass timber in North America” https://www.awc.org/pdf/education/des/ReThinkMag-DES610A-MassTimberinNorthAmerica-161031.pdf