Toronto is unique in having its own mandatory energy and environmental standards for new buildings, called the Toronto Green Standard. The purpose of this project was to provide the City with recommendations for updating the energy efficiency requirements under the Toronto Green Standard. The first phase of the project involved a detailed review and comparison of mandatory and voluntary energy efficiency standards across North America and their potential impact on energy use and GHG emissions. In the second phase, a detailed cost-benefit analysis was undertaken to understand the economic feasibility of achieving various efficiency standards for a variety of different archetype buildings. The key recommendation is that all new mid- and high-rise buildings in Toronto should be required to exceed the energy efficiency requirements of the 2012 Ontario Building Code by 15%.