Canada Wood R&D on High Seismic Performance & Energy Efficient Shear Wall

In an effort to reduce GHG emissions by 46% by 2030, the Japanese government has recently enacted changes to the Energy Efficiency Act, which promotes the use of wooden buildings and mandates adherence to new standards, while also encouraging the use of Zero Energy Homes (ZEH). Starting in 2025, The Building Efficiency Act will require all new housing to meet these new energy efficiency standards. These stricter requirements will significantly impact the structural design practices of home builders. Meeting the new energy efficiency and ZEH housing standards will necessitate widespread use of solar photovoltaic panels on roofs, as well as doubling the amount of heat insulation materials in walls and roofs. As a result, single-family housing will become heavier than current homes, which will consequently increase the seismic load.

This increased mass will require additional shear wall strength for zero energy homes, and structural calculations must be carried out to ensure building safety. Essentially, the Japanese housing market is evolving to demand shear walls that provide added seismic resistance and facilitate higher energy efficiency performance. However, using standard shear walls under these new regulations would necessitate an impractical number of shear walls in housing designs. While Canada Wood has developed the Midply high-performance shear wall (MPW), it lacks the necessary depth to include the insulation required to meet the new energy efficiency standards.

In the past fiscal year, Canada Wood initiated the first phase of an R&D project to develop a new shear wall that meets both new seismic and energy efficiency requirements. Preliminary tests were conducted in March 2024, and the results showed that the new shear wall design could meet the new standards. Expanded 2×6-based wall cavities and stud assemblies provide greater seismic resistance and depth for the installation of insulation materials. These newly developed shear walls will be suitable for use in residential, mid-rise, and non-residential applications. In fiscal year 2024-2025, Canada Wood will conduct phase 2 of this project to refine wall specification designs that optimize seismic and energy efficiency performance while remaining cost-competitive and easy to fabricate. These refined wall specifications will serve as the basis for accreditation under Japan’s 2×4 building code.