Tall mass timber code changes receive final approval

The International Code Council (ICC) has approved all 14 of the tall mass timber code change proposals.

The proposals create three new types of construction (Types IV-A, IV-B and IV-C), which set fire safety requirements, and allowable heights, areas, and number of stories for tall mass timber buildings. The new provisions will be included in the 2021 International Building Code (IBC).

The three new types of construction that will be included in the 2021 IBC are:

· Type IV-A – Maximum 18 stories, with gypsum wallboard on all mass timber elements.

· Type IV-B – Maximum 12 stories, limited-area of exposed mass timber walls and ceilings allowed.

· Type IV-C – Maximum 9 stories, all exposed mass timber designed for a 2-hour fire resistance.

“The addition of tall mass timber to the International Building Code provides a comprehensive set of safety standards for these new types of construction,” said American Wood Council Vice President of Codes & Regulations Kenneth Bland, P.E., in a news release. “This vote caps off several years of scientific research and testing, and verifies that mass timber meets the robust performance standards called for by our nation’s building codes.”

New York City has two very large buildings dedicated to answering the 911 calls of its five boroughs. With more than 11 million emergency calls annually, it makes perfect sense. The second of these buildings, the Public Safety Answering Center II (PSAC II) is located on a nine-acre parcel of land in the Bronx. It’s an imposing 450,000 square-foot structure—a 240-foot-wide by 240-foot-tall cube. The gleaming aluminum cube risesthe equivalent of 24 stories from behind a grassy berm, projecting the unlikely impression that it might actually be floating. Like most visually striking structures, the building has drawn as much scorn as it has admiration.