Sydney's A$915 million Powerhouse Parramatta opens with a 12,000-tonne steel exoskeleton

Paris-based Moreau Kusunoki designed the museum with Australian practice Genton. The three-layer lattice works as both facade and structure, Dezeen reported, and wraps two blocky volumes totaling about 30,000 square meters that connect on the upper levels. Architect Nicolas Moreau told Broadsheet the aim was to move the structure to the exterior. Broadsheet put the steel at 12,000 tonnes, spread over seven levels, and said the brief asked for a 100-year design life.

The payoff is clear span. The largest gallery, Exhibition Space 1, covers more than 2,000 square meters under an 18-meter ceiling and is billed as the biggest column-free exhibition space in Australia, according to Dezeen. A five-part mechanical door lifts to open it onto a terrace by the river. In all, the museum has more than 18,000 square meters of public and exhibition space, with seven column-free galleries, The Art Newspaper reported.

The site sits on the river's flood plain. Experts warned a parliamentary inquiry before work started that heavy rain would flood the open undercroft facing the river, and the design was changed, The Art Newspaper reported. Former trustee Kylie Winkworth told the paper she still fears for people inside during overland flooding.

The museum opens without chief executive Lisa Havilah, who stepped aside in August while the state investigates governance and procurement; she denies wrongdoing. Mark Wilsdon, the chief operating officer, has been placed on leave as the law firm Lander & Rogers examines the allegations, and the matter has been referred to the state's anti-corruption commission, The Urban Developer reported. In August, The Sydney Morning Herald put pre-opening spending at more than A$70 million, including A$10 million for LED screens and staging for one artist's installation.