The residential building end-use sector represents one of the world’s most significant CO₂ producers and energy consumers. As principal endpoints of an aging power system within the US, these consumers are faced with compounding reliability concerns and necessitate innovative solutions to address ever-increasing power demands. To mitigate these issues, novel systems need to be developed to minimize buildings’ overall impact on the grid in a real-time approach. One such improvement is to retrofit existing buildings with an energy monitoring system which can support such a strategy. In this paper, a design for an IoT-based smart monitoring system is developed to achieve reduced overall energy consumption. Economical, low-power current transformer (CT) sensing units are implemented inside an AC load panel within a residential home to monitor the heaviest electrical loads, focusing efforts on the HVAC system and the heat-pump driven water heater. Data from these sensors are collected via IoT microcontroller units (MCUs) and maintained within a real-time database on an in-situ server. This could then be used for “faster than real-time” modeling of the electrical loads of a residential building.