TALL TIMBER:
Height & Hybrids

The Skyscraper Museum continued its Mass Timber semester series, which brings together key voices in the Mass Timber movement to reflect on its short history, current condition, and promising future, with an in-person program held at the office of engineering firm Thornton Tomasetti, at 120 Broadway in lower Manhattan.

How do we increase and optimize the uses of Mass Timber in the building industry? One approach is taller buildings, another is many, many mid-rise structures. Optimizing the amount of wood incorporated in new buildings – while following the best practices of managed forestry and whole-life-cycle analysis – reduces the impact of the high “carbon cost” of the embodied carbon in the energy-intensive standard building materials, steel and concrete, in new construction.

Yet concrete and steel have their own virtues in high-rise construction. A panel of experts capped our lecture series The Short History and Promising Future of Tall Mass Timber Buildings with a discussion of Height & Hybrids. Our speakers included structural engineers and Mass Timber specialists Benton Johnson of SOM, Alejandro Fernandez of Thornton Tomasetti​, and Eric Karsh of EQUILIBRIUM who were engaged in discussion with Daniel Safarik, Director of Research at the Council on Tall Buildings and Urban Habitat ​and co-author of the recent CTBUH Technical Guides​ on Tall Timber. They reviewed a decade of research on timber towers and discussed promising new directions and territories.

The Museum thanks Thornton Tomasetti for the generous donation of their event space for this program.

Benton Johnson is a Structural Engineering Principal in SOM's Chicago office, where he leads the firm's timber tower research project, a multiyear initiative involving full-scale structural, fire, and acoustic testing of mass-timber systems. His work has advanced hybrid mass-timber systems such as timber-concrete composite floors through testing, published design guides, and built work. His innovative approach to structural engineering results in efficient and sustainable designs that are applicable to a wide range of building typologies from supertall buildings to single family residences. He is a Licensed Professional Engineer in multiple states and a LEED Green Associate.

Alejandro Fernandez is a Vice President in Thornton Tomasetti’s Chicago office. As a part of the Building Structure practice at Thornton Tomasetti, he has contributed to Ascent in Milwaukee, Wisconsin, currently the world's tallest Mass Timber building. He specializes in the use of mass timber as a construction material and continues to explore his findings on several notable timber projects in the United States.

Eric Karsh began his structural engineering career in Ottawa in 1987 and in 1998 founded Equilibrium Consulting in Vancouver, British Columbia. Karsh is a leader in Mass Timber engineering and construction and sustainability-focused design. He is co-author with architect Michael Green of the 2012 and 2017 The Case for Tall Wood Buildings, which spurred global discussions on the topic of timber high-rise construction of 20 to 30 stories in seismic zones. Karsh is a Fellow of the Institution of Structural Engineers in the UK, a director of Design Build Research (DBR), and part owner of BC Passive House, a prefabricator of wood-based, high energy efficiency building systems.

Daniel Safarik is Director, Research and Thought Leadership at CTBUH, and has co-authored numerous of the Council’s Technical Guides, including Tall Timber: Mass Timber for High-Rise Buildings. He has served as CTBUH’s Editor-in-Chief from 2013 to the present, and as the Director of the China Office of CTBUH at Tongji University, Shanghai, from 2015 to 2017, spearheading the Council’s efforts to expand influence and membership in China.

The video begins with a welcome and introduction by Museum Director Carol Willis, followed by presentations by Eric Karsh, Benton Johnson, Alejandro Fernandez, and Daniel Safarik, who then moderates the Q&A.