Leith is the Founder and Developer at Assembly. For 40 years Leith has focused on innovating urban development. In 2016, he founded Waverley Projects Inc. to focus on mid rise, transit-oriented development. Previously, he was Senior VP Development at Fieldgate Urban and VP of Development for the Sorbara Group of Companies. He is also Past Chair of BILD, Past President of OHBA, and Past Chair of Evergreen. Leith served on two Provincial Advisory Panels – the Golden Panel and the Crombie Panel.