This research evaluates one method of increasing the performance of an air sourced heat pump to extend its operating range and eliminate the need for a backup heating system. A study was conducted using the Engineering Equation Solver software package to identify the performance improvements that are attainable with variations of a two stage heat pump cycle. An experimental apparatus was constructed to compare the performance of the best performing variation - a two stage economized cycle - to that of a traditional single stage heat pump. The two stage economized heat pump had a measured coefficient of performance of 1.45 when it was operated at an outdoor temperature of -31C making it an energy efficient option for most Canadian climates. In addition, the heating capacity of the system was increased by a factor of 2.5 when compared to the single stage system.