London’s latest pavilion in the park opens on Friday. The appearance of an ambitious, radical building next to the Serpentine Gallery in the city’s poshest park, Kensington Gardens, has become one of the most eagerly awaited fixtures in the art year. But it is not alone. The city is seeing a flourishing of sculptural, architectural booths, kiosks and pavilions.

What has led to this sudden flowering of mini-architecture? Partly it must be the enjoyment of a quick turnaround. Architecture is the slowest of all the arts; it can take a decade from initial brief to completion. These little structures offer a kind of instant gratification for both client and designer. But they also allow a radical experimentation that would be impossible in the world of commercial architecture because of cost and risk.