This paper explores opportunities for, and impacts of potential regulated energy performance and emission reduction standards for existing buildings in British Columbia. It includes evaluation of four standards – Standard 100-2015, Standard 90.1-2010 (BC Building Code), National Energy Code of Canada for Buildings-2015 and retro-commissioning procedures. Standards are applied to the existing building stock, except low-rise residential buildings, at the time of existing building alterations or repairs that trigger the BC Building Code or Vancouver Building Bylaw.