This work focuses on the parametric sizing and performance evaluation of a water glycolto-water transcritical CO₂ heat pump water heater to meet the space conditioning and water heating loads of a Canadian single-family home. A commercial transcritical CO₂ heat pump water heater was retrofitted, and a performance map was developed under steady state testing. An empirically derived performance map was developed to investigate the energetic and economic feasibility of a solar-assisted heat pump system in seven cities located across Canada. This system was designed to meet the space heating, space cooling, ventilation and domestic hot water loads of a Net-Zero energy building archetype. The mechanical system design and building performance model were developed in TRNSYS and the component models were experimentally validated. The simulation model was used to develop 1440 scenarios in a parametric sizing study to represent the diverse climate locations across Canada. For the parametric sizing study, the solar collector size, heat pump capacity, and sensible storage tank volumes were varied. Simulation results show that the system demonstrates efficient solar energy collection, storage, and utilization during the heating season, however, the system’s performance during the cooling season is poor. This reduced performance is attributed to inefficient solar resource utilization, higher heat pump energy consumption, and frequent overheating of the sensible storage tank. Overall, the economic feasibility of the proposed system is found to be poor for all scenarios except for those corresponding to the cities of Whitehorse, Winnipeg, and Calgary.