Dai-ichi Life Completes Hybrid Wood Multifamily Project “Primal Shinagawa Oimachi” in Tokyo

Dai-ichi Life Insurance Company, with technical support from Shimizu Corporation, has completed the development of the rental apartment building Primal Shinagawa Oimachi in Oi 4-chome, Shinagawa Ward. The property was delivered on February 13, 2026. It is the first multifamily rental project in Japan’s life insurance industry to adopt a hybrid wood structure (reinforced concrete plus timber). Compared with a conventional reinforced concrete building of similar scale, the project reduces CO2 emissions by approximately 7%.The property rises nine stories above ground and comprises 38 residential units (20 one-bedroom units, 16 two-bedroom units and 2 three-bedroom units), with a Gross Floor Area of approximately 752 tsubo (approx. 24,860 sq. ft.). The building fully incorporates Shimizu’s proprietary timber construction technology, “Shimizu Highwood.” By eliminating dropped ceilings along the window line, the design creates open sightlines and a sense of spaciousness that is uncommon in typical rental apartment developments.In Tokyo’s central districts, urban timber construction is gaining traction. Mitsui Fudosan began construction in November 2025 on a hybrid wood office project in Nihonbashi-Honcho that will feature upper floors built entirely of timber, signaling accelerating momentum in large-scale urban wood development.For Dai-ichi Life, the Shinagawa project represents its third hybrid timber structure, following TD Terrace Utsunomiya (completed 2022) and Dai-ichi Life Kyobashi Kino Terrace (completed July 2025). Kyobashi Kino Terrace, a 12-story, 56-meter-tall office building, was the tallest hybrid wood office building in Japan at the time of completion. The project utilized approximately 1,100 cubic meters of timber and achieved an estimated 37.5% reduction in CO2 emissions compared with a similarly sized steel-frame structure.As an institutional investor, Dai-ichi Life has introduced preferential underwriting criteria for ESG-qualified real estate investments. Based on its view that ESG properties offer stronger income durability and lower risk, the company has lowered its minimum required yield hurdle by roughly 10% for qualifying assets. The expansion of hybrid wood construction into multifamily rental housing marks a further extension of its ESG investment strategy.In the Oimachi area, JR East’s large-scale redevelopment initiative, “OIMACHI TRACKS,” is scheduled to open in March 2026. The project forms part of a broader development strategy positioning the corridor between JR Hamamatsucho Station and Oimachi Station as the “Greater Shinagawa Area.” The completion of Primal Shinagawa Oimachi coincides with this phase of area value enhancement, drawing attention as a development that combines differentiated timber-based design with strong neighborhood growth fundamentals.

Key Facts

• Property Name: Primal Shinagawa Oimachi

• Owner / Developer: Dai-ichi Life Insurance Company

• Architect: Shimizu Corporation

• General Contractor: Shimizu Corporation & Nihon Kensetsu Joint Venture

• Project Management / Property Management: Sogo Jutaku Co., Ltd.

• Location: 4-17-16 Oi, Shinagawa-ku, Tokyo, Japan

• Completion: February 13, 2026

• Number of Floors: 9F

• Structure: Hybrid Timber Structure (Reinforced Concrete + Wood)

• Gross Floor Area: Approx. 752 tsubo (approx. 26,757 sq. ft.)

• Total Units: 38 units (20 × 1LDK, 16 × 2LDK, 2 × 3LDK)