Techno-economic feasibility of air to water heat pump is assessed for Canadian houses. A state-of-the-art housing stock model is used for techno-economic analysis. AWHP retrofit reduced 36% of end-use energy consumption in the Canadian housing stock. AWHP retrofit decreased 23% of GHG emission of the Canadian housing stock. Aerothermal energy captured by HP can be assumed as renewable energy in most provinces.