The phrase "ephemeral architecture" might sound like an oxymoron at first: one thing would seem to imply impermanence, the other solidity and longevity.

But just as there are pop-up boutiques, there can be pop-up architecture – and if you pay a visit to the NGV's Grollo Equiset Gardens over the summer, you'll see an example.

As part of its new Contemporary Design and Architecture department – launched this March – the gallery has devised an annual Summer Architecture Commission, whereby architects and design firms can submit plans for an ephemeral work that can be dismantled at season's end.

"Exhibiting architecture is part of our remit, so these commissions are a great way of linking ideas about architecture to our audience," says Ewan McEoin, senior curator of contemporary design and architecture at the NGV.

The first work on display is a nine-metre-high, 18-metre-wide polypropylene canopy of hand-folded, origami-like fuschia blooms. This commission was extended by invitation directly to Melbourne architect John Wardle, but from next year the initiative will be an Australia-wide competition judged by a panel of industry experts.

Wardle's piece – designed and constructed entirely in Melbourne – is inspired, in part, by the shape of the Sidney Myer Music Bowl. It will host events over the summer, from live music to design-focused talks in conjunction with RMIT University to a children's festival.

"The idea was to enliven this urban space which is dominated by concrete so that there's a sense of 'play' between our gardens and the brutalism of the main building," McEoin says.

"We really wanted to extend the gallery outwards and make more use of it. I'm also pretty sure a bunch of people will get married in it over the summer."

John Wardle's canopy is on display until May 1, 2016 in the Grollo Equiset Garden.