Architect Nic Brunsdon is explaining the concept behind his giant inflatable sphere, when he's momentarily distracted by how much it's moving in the wind.
At more than 14-metres high, (This is) Air is the latest instalment in the National Gallery of Victoria's annual architecture commission series, and it responds to the breeze by swaying slowly and a little disconcertingly.
"It was designed for the wind - this is about as much as it's ever moved," he told AAP.
The sphere is made from an inner and outer synthetic fabric shell supported by a weighted steel base, that "breathes" by inflating and deflating over a five-minute remotely controlled cycle.
While the giant white balloon is waterproof and can be collapsed entirely in bad weather, Brunsdon is putting the design to the test ahead of its official opening Wednesday night.
The installation is a meditation on the universal qualities of air, he said, that's intended to make the invisible, visible.
"It's a fundamental defining feature of life on earth, from the first breath to the last."
The sphere's outer shell measures 14.5m across and when fully inflated, its volume approximates how much air a person breathes in a year.
Brunsdon's architecture firm works out of Perth, Bali, and Melbourne, having designed the award-winning Bali hotel The Tiing and North Perth House, a residential building made from arches that was featured on Grand Designs Australia.
He came up with the design in a flash of inspiration while he was getting a massage, and since winning the NGV's annual architecture competition, the project has taken a year to develop in collaboration with art and design studio ENESS.
The 2023 commission also means the NGV's backyard has returned, after being part of Temple of Boom's re-imagining of the Parthenon in 2022, and the year before that, a much-loved pink pond.
Brunsdon's inflatable might bring to mind questions of air quality, China's satellite balloons, or even, for Melbourne foodies, a giant burrata.
"We don't want to dictate how people understand it. It's supposed to be a bit of a weird invitation," he said.
The 2023 NGV Architecture Commission: (This Is) Air is on display at NGV International, St Kilda Road, from Thursday.
