The Ariake Gymnastics Centre is designed to function in two phases; initially as a temporary international sports competition facility, then, after taking out the temporary spectator stands, it will be converted into a permanent exhibition hall. A unique feature of this facility is its extensive and generous use of timber throughout the building. The material was selected to express the memory of the site which was once a timber storage pond. Timber is used wherever possible, specifically in the roof frame structure, facade, spectator seats, exterior walls, etc. while carefully considering the characteristics of wood in each application. The arena ceiling is a wood frame structure designed to reduce the weight of the overall structure. The concourse space, where spectators approach the arena, is intentionally placed outdoors. The wood facade takes into account acoustic and thermal insulation properties. Function, structure, and space are tightly combined to achieve beauty and richness in simplicity, which is the essence of Japanese traditional wood architecture that we hope spectators and athletes from all over the world will experience.