Construction of a new stadium was the dream of Gamba Osaka from 2007. Their home ground at the Expo 1970 complex was already behind international regulations or actual expectations of football fans.
Described as 3D, the roof structure consists of primary trusses placed in 3 directions (thus the name). Using this layout allowed to cut amount of steel by 40% and also makes the structure able to withstand earthquakes. Not only the steel, but energy and water consumption were targeted to be efficient. Half of the water (5,500 tons) used by toilets will be collected during rainfalls, the roof has a 500kW solar power plant (equivalent of 184-household use), while floodlights are Japan’s first LED system, reducing electricity use by 27%.
Efficiency was also crucial when planning the floor space. The stadium in Suita has Japan’s largest skybox/hospitality offer and at the same time may serve as emergency storage (480 square meters) or shelter for up to 800 residents (short term, fewer for longer periods). This use is among factors that gave it some public funding.
Construction cost was estimated at ¥15 billion in 2008, but eventually proved lower despite extra capacity. It went slightly above 14 billion, of which public authorities contributed ¥3.25bn. Vast majority came from private donations, primarily corporate (9.95bn). Thousands of people who offered their money (622m) were then invited for a community day on October 10, 2015, long before opening.