Hajime Kensetsu Co., Ltd. to Fully Introduce In-House Developed Shear Wall 'HW5.0Σ' with Wall Strength Ratio of 6.3 Starting June 2026, Focusing on 3-Story Homes in Tokyo's 23 Wards

Hajime Kensetsu Co., Ltd. (Headquarters: Toshima-ku, Tokyo; President and CEO: Tadami Horiguchi; hereinafter 'Hajime Kensetsu'), a core company of Iida Group Holdings, announces that it has obtained a patent for its in-house developed shear wall 'HW5.0Σ (Hajime Wall 5.0 Sigma)' on Wednesday, May 25, 2026, and will begin full-scale introduction from June 2026. In recent years, demand for 3-story homes has been increasing in urban areas for effective land utilization. However, achieving high seismic performance while securing living space within limited land area remains a challenge. 'HW5.0Σ' is Hajime Kensetsu's proprietary shear wall developed to address these challenges. 'HW5.0Σ' is Hajime Kensetsu's proprietary technology, the first in Japan to receive ministerial certification as a wooden diagonal bracing wall with a wall strength ratio exceeding 5.0. It is a high-strength, high-ductility, and high-rigidity shear wall that simultaneously enhances design flexibility and reduces construction costs. This technology has been developed as part of Hajime Kensetsu's internal R&D initiative. Moving forward, the company will promote full-scale adoption and implementation, primarily in 3-story detached and multi-unit homes in urban areas such as Tokyo's 23 wards, where demand is growing. Main Features of 'HW5.0Σ' 'HW5.0Σ' enables small openings, built-in wall storage, and routing for utility pipes—features difficult to achieve with conventional wooden bracing walls—allowing flexible floor planning even in compact homes. Unlike conventional braced walls, 'HW5.0Σ' employs a patented central metal connector joining method that minimizes damage to bracing members and columns, thereby achieving superior seismic performance. The wooden diagonal members use domestically produced, standardized LVL (Laminated Veneer Lumber), ensuring consistent quality. Additionally, by reducing the amount of timber used, the technology achieves both enhanced seismic resistance and cost reduction. For detailed structural information and construction case studies of 'HW5.0Σ', please visit the dedicated website 'Hajime no Gijutsu' (The Beginning of Technology). Dedicated Website: https://www.hajime-kensetsu.co.jp/commitment/06/ Future Outlook Since the initial public demonstration of 'HW5.0Σ' in October 2025 at a 3-story condominium project in Itabashi Ward, Tokyo, Hajime Kensetsu has been conducting verification and validation. Going forward, the company plans to expand the range of applicable buildings and promote wider adoption among other residential developers through general sales via collaborative development partners. Additionally, through further technological development, Hajime Kensetsu will continue to provide customers with safe, secure, and comfortable homes. Company Overview: Hajime Kensetsu Co., Ltd. Company Name: Hajime Kensetsu Co., Ltd. President and CEO: Tadami Horiguchi Headquarters: 2-25-5 Minami-Ikebukuro, Toshima-ku, Tokyo 171-0022, Fujikyu Building East No.5 Established: February 13, 1967 Capital: 3.298 billion JPY Business Activities: - Detached Spec Homes: https://www.hajime-kensetsu.co.jp/for-living/ready-built/ - Condominiums: https://www.hajime-kensetsu.co.jp/for-living/apartment/ - Custom Homes: https://www.hajime-kensetsu.co.jp/for-living/custom-built/ - Renovation & Remodeling: https://www.hajime-kensetsu.co.jp/for-living/renovation/ - Asset Solutions (Investment Homes & Land Utilization): https://www.hajime-kensetsu.co.jp/become-an-owner/investment/ - Lease-Back Plus⁺: https://www.hajime-kensetsu.co.jp/become-an-owner/lease-back-plus/