In recent years, the development of laws related to the promotion of wood use in buildings in Japan has led to a significant increase in wood demand, resulting in the widespread use of various wood materials in construction. In this context, the use of preservative-treated wood, selected based on the principle of using the right material in the right place, has been emphasized. However, a systematic evaluation criterion for promoting resource circulation and realizing a circular economy for exterior products remains unestablished. To support the selection of environmentally conscious wooden exterior products that contribute to the realization of a circular economy, this study attempts to propose a systematic evaluation criterion for exterior products. Evaluation items and criteria were set, and the gazebo and observation deck constructed with design and construction methods carefully considered to achieve higher scores based on these criteria. When comparing the evaluation of wooden products with innovative construction methods, wooden products with standard construction methods, and products combining steel and composite wood with standard construction methods, the wooden products with innovative construction methods received higher scores than the other products. From this, it can be concluded that the proposed evaluation criteria can effectively assess wooden products with consideration for circular economy principles. Additionally, as a synergistic effect of using wooden products assembled with improved methods, an enhancement in biodiversity is expected, and improvements in material yield were achieved on-site. In the future, we aim to incorporate perspectives such as "biodiversity," "on-site material yield" and "use of local materials" into the evaluation criteria and continue refining them. Additionally, to clearly communicate the approach to manufacturing with a focus on the circular economy, we are considering introducing a ranking system based on scores to make it easier to understand.

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