The building has hosted hockey games and concerts over the years. It was also the headquarters for the "yes" and "no" camps at the height of the 1995 referendum on sovereignty.
Architects will preserve the Art Deco look of the building and will restore 20 per cent of the original brick. They will create a central, open-ended common space with a view of the river on one side, and the city on the other.
It will maintain its 3,700 seating capacity. The renovations are expected to cost $26 million and will be paid for by the city and borough.