An enormous greenhouse will be built nine metres above Queen Street in 2017 as part of a major redevelopment of the Queen Victoria Market.

The new pavilion, which will cost $5 million to build, will run from Victoria Street to just north of Franklin Street. At 260 metres long and 16 metres wide, that will make the new conservatory the longest inner-city greenhouse in the world, according to the City of Melbourne.

The structure – which will sit on nine-metre columns, suspended above a space that is currently a carpark – is supposed to be temporary and will house fruit and vegetable sellers during the $250 million market redevelopment.

“You would normally find these kinds of greenhouses on agricultural land, so it will be incredible to have one of this size in the heart of Melbourne,” Lord Mayor Robert Doyle tells Broadsheet.

“You have to offer people a real experience when it comes to selling food, and this greenhouse does just that. It’s about walking among the produce and finding a spot to sit down and enjoy some food – maybe with a glass of wine – in a green, open space.”

On 40-degree days, the inside of the greenhouse will only reach about 28 degrees thanks to the evaporative-cooling effects of a productive greenhouse, the City says. It will also house a ‘biodigester’ that will recycle waste from the market, such as food scraps, for use in fertiliser in the greenhouse.

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Four architecture firms pitched designs for the pavilion. A panel – which included five market traders – chose a concept by Melbourne-based architecture firm Breathe as the winning submission.

“It can be dismantled and re-sold once the entire redevelopment is complete,” says Mayor Doyle. “I suspect it will become a much-loved part of the market and people will be telling us to keep it.”

Construction on the market is expected to start in early 2017, and fruit and veg traders will move from their traditional sheds into the greenhouse in September.

More information about the Queen Victoria Market redevelopment is available here.