So much time, planning, effort and money - and back room deals, of course - go into planning. But imagine if you had the opportunity to be part of the 'building' process without having to get your hands dirty. Well, a group of 10 Sydney artists are working on it, with a project called Air City. It's an inflatable architecture, but it's part of the public lab at this year's Underbelly festival, so it's a work in progress - three of the artists, Tully Arnot, Charles Dennington and Xiaofu Wang joined Matt Levinson to discuss how it was going.