Constructive conflict: can design competitions make cities stronger?

In recent years, public contests have been used for everything from the New York 'Dryline' to a new Guggenheim. But do these competitions just encourage gimmicky ideas - or are they a better way to prepare cities for a changing world?

Just as musicians can build their year around festival appearances, architects can now fill their calendar with deadlines for design competitions. The international contest is an increasingly fashionable way of generating new ideas, forging reputations and getting some interesting things built.

We have competitions to thank for New York's 9/11 Ground Zero Memorial and Manhattan's High Line. Thomas Heatherwick's controversial plan for a Garden Bridge across the Thames was commissioned by Transport for London after a design contest. And more than 1,700 entrants sought the chance to create Helsinki's Guggenheim museum before the bid by Paris-based architects Moreau Kusunoki was eventually selected.