A common question about submetering is: what happens to the electricity used in common areas? The answer is straightforward. Common area electricity stays on the building's account. It is not shifted to individual residents.
Common area loads in a typical multi-residential building include hallway and corridor lighting, lobby lighting and equipment, elevator motors and controls, parking garage lighting and ventilation, common laundry rooms, mechanical rooms (pumps, fans, boilers, chillers), and exterior lighting and landscaping.
When submetering is introduced, the building's total electricity bill is split into two streams. In-suite consumption is billed to individual residents through the USMP. Common area consumption remains on the building's bulk account and is paid by the corporation or owner.
This split is important for budgeting. Boards and property managers should estimate what percentage of the building's total electricity is common area versus in-suite. This varies widely by building type. In a typical older apartment building, in-suite consumption might represent 60 to 70 percent of total building electricity. In a building with extensive common amenities, the common area share may be higher.
After submetering, common area electricity remains a controllable operating expense. Buildings can reduce common area costs through LED lighting upgrades in corridors and parking, occupancy sensors in low-traffic areas, variable frequency drives on pumps and fans, timer controls on exterior lighting, and regular maintenance of mechanical equipment.
Property managers should track common area consumption separately to identify opportunities for efficiency improvements. Some submetering systems can monitor common area loads alongside suite-level metering, providing a complete picture of the building's electricity profile.