Resist temptation to go straight up

Olafur Eliasson's The cubic structural evolution project, 2004, Auckland Art Gallery, courtesy of Queensland Art Gallery Foundation Grant, purchased 2005. Photo / John McIver

Go play with the 12m of white Lego in the Auckland Art Gallery main atrium - it's great fun, it's free and it's there for six months.

It might sound like utter freedom - the gallery's press release says you're "limited only by your imagination" - but that's not quite true. For a start, you're always limited by your materials. Lego isn't playdough so it's not great for irregular, curved shapes. The pay-off is that Lego's clean-cut, lantern-jawed and straight-edge pixilation makes it much easier for even us non-artistic types to construct impressively regular right-angles.

Another limitation is our yearning to conform. The expected, easiest thing to do is to build a tower. Some stunners rose on the opening day: a love heart on a pedestal, a triple helix spiral, a flagpole that looks like a third cousin to the Eiffel Tower.

Towers are expected not just because the Lego table faces the Sky Tower but also because the wall-text for the touring artwork - titled The cubic structural evolution project, by Icelandic-Danish artist Olafur Eliasson - invites us to be "architects" and "builders" of a "cityscape".

Cities, in our collective imagination, apparently require futuristic towers. The monochrome Legos make this a crystal city rather than the Emerald City of Oz. Someone has even made a sturdy construction crane, dangling a diamond as big as the Ritz.

Towers are also easy, because Lego's brick buttons connect vertically, not horizontally. Also, space is at a premium, just like - learning moment - it is in many cities. And if you want your creation to get noticed, high is the only way to go - low-rise gets lost against the rubble-jumble of loose bricks. This is no sprawling Lagos of Legos.

Dunedin Public Art Gallery exhibited the art work over winter, and on the first day there people raced to build the highest tower. This is literal aspiration - to erect the tallest spire. Though the press release mentions community and collaboration, participants can have fun being as competitive as jazz-age Modernist capitalists.

It's a micro-metropolis in time as well as space: after a while, old towers will be demolished and new ones will rise in their place. It's the Danish equivalent of a temporary Buddhist sand mandala. This is great: permanently frozen Lego would shut down the bricks' ever-changing potential.

But, enjoyably, towers weren't the only creations on Auckland's first day. There was also a robot, a cat, a pair of helicopters. Most originally, a dog was balanced on top of a pair of scales - was this a comment on our former Minister of Justice? The message spelled in bricks was: STOP.

Limitations aren't bad; thinking up responses to them stimulates creativity. But it's good to know which limitations you can change or challenge if you choose to do so. Over future lunch-hours I'll follow the artist's city idea, but will resist the temptation of the tower.

Maybe I'll attempt a tree, maybe a monorail. Maybe a crystallised homage to the politics of urban discourse. It's gonna be breathtaking.