40 / BUILDING DIALOGUE / September 2021 ELEMENTS Mass Timber Timber for Tomorrow: Mass Timber Construction for MF I t’s official, the building code has changed. The International Building Code’srecentexpansionofType IV (heavy timber) construction to include buildings of up to 18 stories has made building high- er with wood possible. Utilizing heavy timber as a primary struc- tural system for new multifamily developments expands opportuni- ties but also raises questions. At a time when cities across the nation struggle to meet housing needs, the expansion of mass timber construc- tion supports increased residential development and addresses some of the challenges facing high-density multifamily construction projects. As an alternative to concrete or steel structural systems, mass timber pro- vides another design solution with distinct material properties. • Lower cost. Woodconstructiongenerally indicates a lower-cost design solution when compared with concrete or steel. Even with the recent price increase in lumber, the cost of wood is still consistently lower than other high-rise options. After reaching a record high in May, the lumber industry is already seeing prices begin to drop and the market expects prices to continue decreasing as recent disruptions in the lum- ber supply chain begin to stabilize. • Better for the environment. The environmental benefits of selecting mass timber over concrete or steel are clear. As a renewable resource, wood offers a solution associated with inherently lower embodied carbon. Additionally, theuse of cross-laminated timber or other wood-based engineered products minimizes construction waste and provides exceptional design flexibility. The increasing severity of wildfires in the West and hurricanes in the Southhavehighlighted the incipient environmental crisis that demands new solutions for construction innovation to reduce the construction industry’s effect on climate change. Building materi- als and construction contribute roughly 11% of total global greenhouse gas emissions (United Nations En- vironment Global Status Report 2017).Within that 11%, Marissa Kasdan, Associate AIA Director, Design, KTGY’s R+D Studio KTGY’s R+D concept Timber Tower includes a sweeping ground-floor lobby space featuring a natural design aesthetic. To maximize parking within a mass timber structure, mechanically stacked parking fills a single-level garage at the ground floor of Timber Tower.