The firefighter’s work environment is constantly evolving with the introduction of new consumer products and new construction materials and practices. This class updates the information and testing results related to mass timber buildings. The International Code Council is considering multiple proposals that will permit the tripling of permitted heights and areas. The focus is on tactical considerations or programs fire departments may need to implement should this type of structure be proposed for their jurisdiction and the hurdles the expansion of the proposed mass timber industry faces in the current market. Another area of concern addressed is large lithium-ion battery systems, which permit smaller batteries with much greater density, a combination that can present challenges to the responding fire companies. Students learn of programs their departments can implement preinstallation to ensure the proposed systems are evaluated for potential failure and the results of such a failure.