Tall Mass Timber Trends and Exposed Timber Allowances

Analysis of recent code changes and jurisdictional approvals providing for greater areas of exposed mass timber in tall buildings. Covers trends showing over 80% of tall mass timber projects are in 6-12 story range, motivated by aesthetic appeal and market differentiation of exposed wood. Examines differences between construction types regarding timber exposure allowances, evolution from 20% to 100% ceiling exposure in Type IV-B construction between 2021 and 2024 IBC. Documents full-scale compartment fire testing at Research Institute of Sweden (RISE) that supported 2024 code changes, including test results demonstrating safe performance of 100% exposed timber ceilings. Addresses practical considerations for multi-family vs office applications and variance approval strategies.