Housing stock in cold-climate countries: Conversion challenges for net zero emission buildings

The residential sector is responsible for 11.7% of global greenhouse gas (GHG) emissions. Space and domestic hot water (DHW) heating accounts for about 80% of the energy consumption of households in cold-climate regions. This study investigates the status of the housing stock in a set of cold-climate countries (i.e., Northern Europe and Canada) with the goal of identifying the barriers to achieving net zero emission (NZEm) status in the residential sector. Several parameters are analyzed, including vintage, energy mixture for onsite heating and offsite electricity generation, energy use, and GHG emissions intensities. Potential scenarios of energy supply and their impact on energy consumption and GHG emissions of the residential sector are discussed. Results show that the existing houses are not energy efficient, and it will be a challenge to reduce the GHG emissions of the residential sector. The energy outlooks indicate that the carbon intensity of grid electricity would not be zero due to reliance on fossil fuels. Therefore, an existing household could not achieve NZEm status by solely using grid electricity. Deep energy retrofits, renewable energy technologies, and reducing the carbon intensity of energy sources are measures to be implemented to achieve NZEm status for the residential sector.