Spectator stands are being built at 43 venues for the Tokyo Olympics, despite the possibility that they may need to be redesigned to comply with capacity limits.
The Games are scheduled to open on July 23. They were postponed last year due to the coronavirus pandemic.
The organizing committee is set to decide on spectator numbers by spring.
At a venue for events including sport climbing, a stand with a capacity for 8,000 spectators is being rebuilt. It had been almost complete by March last year, but was dismantled to prevent decay following the postponement of the Games.
Construction work is also underway at a triathlon venue and a canoe slalom facility.
The committee says the postponement of the Games has led to an additional expenditure of 294 billion yen, or about 2.8 billion dollars. About 695 million dollars of that has been earmarked for rebuilding spectator stands and other temporary facilities.
Otemon Gakuin University Associate Professor Uebayashi Isao says organizers need to decide how many spectators will be let into venues as soon as possible, and what kind of vision they have for the Games.