Two years after it was closed to the public amid fears its marble cladding would fall on pedestrians, one of Collins Street’s best-known office towers is to be knocked down.

But a city heritage group says it is a pity the building is to be lost, and that Melburnians would be wise to put greater value on such modernist buildings.

Melbourne City Council has given Cbus Property a demolition permit for the former Suncorp building it owns on the corner of Collins and William streets.

The 27-level office tower was built by National Mutual in 1965 on the site of the former Western Market, which had operated there for more than a century.

In January 2012, the building’s major tenant was Suncorp. They and other businesses were forced to vacate following the collapse of parts of the marble facade into the building's forecourt, and the tower and a large open square that fronts Collins Street has been fenced off ever since.