This Toronto Community Housing–managed, 44-year-old, 19-storey apartment complex with ground-level retail operations was in serious need of a retrofit. The building had an aging diesel-fuelled emergency power system, and TCH seized the opportunity to make the system cleaner and more robust, with help from provincial programs. The TCH outfitted the building with a natural gas–fired combined heat and power (CHP) system to provide both emergency power and domestic electricity and hot water. While the CHP system is performing well, its cost effectiveness is limited by high maintenance costs and inconsistent hot water demand. The lessons learned from this pilot site should allow future CHP projects to achieve stronger economic and environmental benefits.