Grollo family proposes pencil-thin tower for CBD New tower for 464 Collins St. Picture: Supplied Source: Herald Sun A SUPER-THIN tower using a revolutionary design has been proposed for a prime CBD site. A member of the Grollo family is behind the push for a 54-storey office and apartment building at 464 Collins St. Dubbed by some as the pencil-thin tower, it would feature one continuous structure of reinforced concrete and look like cutting edge buildings in cities such as New York and Hong Kong. Lorenz Grollo, head of the Equiset-Grollo group and son of construction legend Rino Grollo, said it would be extremely innovative for Australia and its use of concrete was a nod to his family's business heritage. It's slender but it will make an impact. It's done in such a sculptural way that is ultimately unique," he said. "It's not just a glass box, it's a stylish piece of architecture," he said. Designed by architects Bates Smart, the tower will house about 150 high-end apartments and 13 levels of premium office space. The facade of an existing Edwardian-era building will be incorporated. Planning Minister Matthew Guy confirmed a permit application was before his department and he would make a decision after input from his staff and city council officers. "It's a very interesting design and it's looking at innovative ways to optimise space," he said. Mr Guy has approved several highrise towers in the CBD, including plans for the southern hemisphere's tallest building at 108 storeys at Southbank.