Paving the Way for Large-Scale Wooden Buildings in Japan: The New HOWTEC Design Manual
The Japan Housing & Wood Technology Center (HOWTEC) has recently released a groundbreaking design and structural calculation manual specifically for large-scale post-and-beam wooden buildings. Known as the “large-scale grey book,” this new guide builds on HOWTEC’s previous manual, which was limited to residential applications up to three stories.
The original grey book lacked essential provisions for larger wooden structures, such as trusses, built-up beams, and high-performance horizontal diaphragms—key elements in large-scale wooden construction. The new grey book fills this gap, providing guidelines for designing wooden buildings up to four stories high.
This publication is a major advancement for Japan’s wooden construction industry. Until now, the lack of a standardized manual created challenges in obtaining project approvals for large-scale wooden buildings. The new large-scale grey book simplifies this process by offering clear guidelines that support both designers and building officials, ultimately facilitating the construction of larger and more complex wooden structures.
Canada Wood Japan has initiated research into the large-scale grey book to explore how B.C. Coastal post and beam components and Canadian dimension lumber can be effectively utilized within this new framework. This research aims to promote the use of Canadian wood in the expanding Japanese market for large-scale wooden construction.