This session is important as buildings are a major contributor to global carbon emissions, with 50% of total energy use and 40% of GHG emissions being attributed to buildings globally. Building envelopes significantly contribute to this energy use as building envelopes are the single largest factor in considering HVAC design, both in terms of sizing and energy consumption. Specifically, building envelopes contribute up to 51% of energy loss of buildings. Such significant energy use, which translates into exorbitant GHG emissions, make retrofits an absolute necessity to meeting global decarbonization goals. The International Energy Agency’s Net Zero by 2050 roadmap states that to achieve net zero by 2050, 85% of buildings globally need to comply with zero-carbon ready building energy codes by 2050. In order to achieve this, retrofits need to be carried out in most existing buildings by 2050, meaning that 10 million dwellings need to be retrofitted per year. QEA Tech has conducted hundreds of energy audits on building envelopes across North America and as such, we have first-hand case studies that detail how significantly the building envelope contributes to the energy loss of a building and the retrofits necessary to mitigate this loss.