Japan’s Top Structural Design Firm Sakura Kozo Launches ‘Select Wood’ for Mid- to Large-Scale Timber Buildings

Sakura Kozo Co., Ltd. (Headquarters: Sapporo, Hokkaido; President and CEO: Shinichi Tanaka), Japan’s No. 1 company by structural design sales, has launched “Select Wood,” a new timber construction service designed to deliver dramatic cost performance for mid- to large-scale buildings. The company has built a top-tier track record in cost optimization for reinforced concrete (RC) and steel-frame (S) buildings. After five years and eight months of research, Sakura Kozo is entering the timber construction market to complete a consulting structure that covers all structural types. From a neutral position unconstrained by any specific construction method or structural category, the company aims to offer “true optimization plans” that prioritize project success for business owners facing severe construction cost inflation. Sakura Kozo has previously focused on proprietary methods for RC, S, and WRC structures, accumulating more than 10,000 design projects. Recently, however, the company has received an increasing number of serious inquiries from clients whose original RC or steel-frame plans no longer fit their budgets due to soaring steel prices and construction delays. The company says it had intentionally avoided actively taking on timber projects until it could be confident that timber construction could deliver seismic performance and economic efficiency surpassing other structural types. While steel prices remain at record highs, timber prices have been relatively stable, and growing environmental awareness has increased expectations for mid- to large-scale timber buildings. In practice, however, such buildings often remain expensive symbolic projects limited to major corporations or public works, creating an opaque market with limited price competition. Sakura Kozo says it has now successfully transferred its structural frame optimization know-how to timber construction, making timber a realistic cost-optimization option for ordinary buildings such as four- to five-story apartment buildings, warehouses, and retail stores. According to the company, “Select Wood” has achieved cost reductions of up to approximately 35% when converting projects from other structural types to timber. Examples include a five-story rental apartment building reduced from 300 million yen in RC construction to 222 million yen with Select Wood, a reduction of about 35%; a four-story office building reduced from 246 million yen in steel-frame construction to 205 million yen, a reduction of about 20%; and a retail store reduced from 192 million yen in steel-frame construction to 175 million yen, a reduction of about 10%. Actual reduction rates vary depending on ground conditions, architectural design, and site conditions. The company emphasizes that its goal is not simply to build in timber, but to propose the optimal structure for business success. If analysis shows that RC or steel-frame construction is better suited to a project, Sakura Kozo says it will not force a timber proposal. If pure timber construction does not meet budget or layout requirements, the company will also consider timber hybrid structures that combine timber with other structural types. The research and development of Select Wood was supported by Associate Professor Takafumi Nakagawa of Kyoto University’s Research Institute for Sustainable Humanosphere, a leading expert in seismic performance research for timber buildings and the developer of wallstat. Sakura Kozo is feeding the latest research on timber seismic performance into practical design while pursuing thorough cost rationalization on a foundation of verified safety. Sakura Kozo has also begun constructing “SAKURA FOREST,” a separate building for its new in-house office, as a demonstration project for Select Wood. The five-story building adopts a timber hybrid structure that combines the design qualities of timber with the spatial flexibility of steel construction. Through the project, the company plans to verify the economic efficiency and constructability of Select Wood in its own building and return those findings to clients. Its official Instagram account will share the process from demolition to completion in real time, and events are planned where visitors can observe the construction of the timber hybrid structure. The company is also recruiting Select Wood partners nationwide, including general contractors, builders, precut timber suppliers, design firms, and equipment companies, to help promote mid- to large-scale timber construction. Sakura Kozo Co., Ltd. is a high-seismic-performance design group that has handled more than 10,000 structural design projects across Japan and ranks No. 1 in structural design sales. The company developed “TSUYOKU,” its own high-seismic-performance standard, and works to enhance the value of structural engineers while promoting the appeal and potential of the structural design industry.