The Japanese government has approved a 150bn yen ($1.5bn, €1.3bn, £1.1bn) contract allowing work to begin on Kengo Kuma’s 2020 Tokyo Olympic Stadium.

Construction is scheduled to begin in December. The government-funded Japan Sport Council (JSC), which is overseeing the project, estimates that construction will be completed at the end of November 2019 – five months behind the original schedule.

New Tokyo Governor Yuriko Koike said she would closely monitor the project, which the city is part-funding. “For the burden we have to share, I will ensure it’s utilised for the people of Tokyo, and raise my voice when necessary,” she was quoted as saying by local media.

The project green light looks to have finally ended a protracted and public saga, which saw a design team led by Zaha Hadid Architects (ZHA) awarded and then stripped of the project amid spiralling costs, accusations and acrimony.

Kuma was then appointed to complete a new design after the JSC were swayed by his vision for a predominantly wooden, tree-surrounded stadium. However, ZHA accused his plans of sharing “remarkable similarities with our original detailed stadium layout and our seating bowl [configuration].”

ZHA director Patrik Schumacher later described the whole saga as “incredibly distressing” and "the biggest setback ever."

In an exclusive interview with CLAD, which will appear in the forthcoming issue of CLADmag, Kuma defended his design and said that while there are some “unavoidable” similarities – such as the evacuation points, the position of the stairs and the layout of the field – his vision for the project “is totally opposite” the one proposed by ZHA.

“The communication between Zaha, the Japanese partners and the client was very bad,” he said. “I think it’s a problem in Japan. For foreign architects to work here is not easy because the system is totally different and a language barrier exists between the Japanese and the foreigners.

“Zaha was very much frustrated with that kind of miscommunication. I understand that difficulty, of course. But I was not happy to hear the claims about our scheme.”

The Japanese architect said his stadium, and the 2020 Games more broadly, will symbolise today’s Japan: a country “whose culture and direction is totally opposite from what went before” due to a slowing down of both economic growth and the pace of life.

“This new direction can be called the age of maturity,” he said. “People are finding a new, slower kind of lifestyle. But slowdown is not bad. Slowdown is creating new types of culture, new types of lifestyle. For the stadium, I have used a lot of wood because I think it’s an appropriate material to symbolise this change.”