Long Span Wooden Structural Beams Assembled with Four Meter long Timbers using Japanese Traditional Connections

“Wooden Hall” is an office building in Tokyo Japan with a signature column-free hall on the top floor covered by a 25 meter long span wooden roof. The wooden roof consists of several wooden structural beams. The wooden structural beams are assembled with four meter long timbers using traditional Japanese connections. While the connections are quite complicated, they have been fab- ricated mechanically and quickly at a sawing factory of timber using modern technology. The spe- cies of the four meter timbers is Japanese cypress and the connection details use evergreen oak. The details used in this project have been substantiated using material tests, connection tests, bending and shearing experiments (full scale), creep experiments (full scale) and fire resistance verification. In addition, this wooden structure is more ecological than a typical steel or reinforced concrete structure helping Japan achieve our goal of a 25% reduction in CO2 emissions.