1 St Clair West is a proposed tower of 49 storeys/165.63 meters in Toronto's midtown. It is to be built atop an expanded 12-storey, 1968-built Modernist office building. Existing retail space at ground level will be improved, office floor plates from floors four to 11 will be expanded, and 340 residential suites are to be built up top. Designed by Gensler for Slate Asset Management.