Mass Timber Pencil Towers; A Possibility or Fiction?

Ross Wimer
Senior Vice President
AECOM, Los Angeles

In the late 19th century during the Industrial Revolution, there were significant advancements made in metallurgical science and industrial manufacturing that led to the advent of tall buildings. Today there is global urgency to make a similar push for advancement in the way buildings are constructed to transform existing practices to be greener. Steel and concrete dominate the tall building industry and account for 10% of global CO2 emissions. The tall building industry needs to take steps forward to provide a scalable timber-based alternative to align with global green movements.
One of the challenging sub-categories of tall building construction is to design and build towers with high slenderness ratio. As urban settings get denser available plots of land also shrink. This is visible in New York, Hong Kong, and a number of other metropolitan cities. The confluence of zoning regulations, sustainability requirements, and capital has created opportunity where mass timber construction can offer significant value.
In this presentation, a proposed 30-story tower (350ft) in Hong Kong with a slenderness ratio of 1:11 is presented. On each floor, only one unit with an approximately 450ft2 takes the full floor space. By developing a novel structural system, which is a synergistic combination of material and engineering design, the stringent lateral stiffness and serviceability requirements were satisfied. A high level of prefabrication overcomes the logistical challenges of working in a tight operational footprint. This presentation seeks to set an example to adopt mass timber construction for skyscrapers with slender typologies and to provide a practical framework for developing scalable wood based structural systems.

Accompanying PowerPoint Presentation