The four sand artists came to Hong Kong to make sand sculptures for the city's Olympic team. Their grand design in Tsuen Wan Plaza used up 30 tonnes of sand. Their tallest sculpture is 3.3 metres. One creation, in homage to the Games' host city, features a double-decker bus, London's Big Ben, and Queen Elizabeth II holding an Olympic torch.
Another showcases our five strongest sports - table tennis, windsurfing, equestrianism, swimming, and cycling - under the city's official flower, the bauhinia.
The idea of building sand castles in a shopping mall may sound unconventional - and even absurd. But not to the artists.
"We have done it a few times in shopping centres before," says Hoggard. The Briton, who with his partner, Geerts, runs Sandartist Ltd, says art galleries, cathedrals or wedding parties aren't strange places to them, either.
But indoor sculpting isn't without challenges. You can't dig down and space can be limited. "We're a bit confined," Geerts admits. "And we have to keep it clean."
But then being indoor also has its benefits. If they had been building outdoors, she says, their sculptures in progress would have been blown away by the recent typhoon Dokursi.
The four artists say they hadn't met any of Hong Kong's Olympic athletes before they started sculpting. But that's okay, Hoggard says. "We're sculptors. If you give us a picture, we reproduce it," he says. "If the picture is two dimensional, we can turn it into three dimensions."
Mutch, a Canadian, and Molina, a Mexican, have collaborated with Hoggard and Geerts several times before. The four artists first met at a major sand sculpture project in Belgium in 2005. Now they are internationally recognised masters of sand sculpting.
Apart from Geerts, who has a degree in industrial engineering, the sculptors all have a background in the arts. They have all chosen sand as their preferred artistic medium because of its accessibility.
"It's a natural resource," says Mutch. Unlike ceramics and other materials, sand is free, he adds.
The group intends to create contemporary art for everyone, and the abundance of sand makes it an ideal medium for them.
In 2006, Hoggard and Geerts were commissioned to carve sand sculptures for Queen Elizabeth at the Royal Cornwall Show. Last year, they created sand sculptures for the Queen of Qatar.
Despite their fleeting nature, sand sculptures can be a lucrative art form. Hoggard owns two big houses and land in Britain.
Yet he insists that financial considerations come a distant second to his primary motivation: his love of sand sculpting.
"Never chase the money," Hoggard advises aspiring artists.
"Always do whatever you're passionate about, and the money will come [afterwards]."
The sand sculpture exhibition will be on show in the atrium of Tsuen Wan Plaza until July 31