Builder Installed Electrical Loads: The Energy Mortgage on a New House

Builder-installed electrical loads (BIELs) are electrical appliances and components installed by the builder prior to occupancy that consume mains electricity. BIELs include products required by building codes, products expected by buyers, and/or products selected by the builder to make the house more attractive to buyers. Reducing the energy use of BIELs may provide an economical opportunity to reduce the miscellaneous electric load in homes, but BIELs are not well understood. To address this need whole house BIEL was measured in 17 new houses. Results showed an average total power of 128 watts, which represents an “energy mortgage” of $135/year before the owner even moves in. The largest loads found were from continuous ventilation fans required by code, but surprises like continuously illuminated street address signs and video doorbells, were also significant. Laboratory measurements of 35 life safety devices were performed to further characterize BIEL energy consumption. Strategies to reduce this energy use include: selection of lowest-power solutions, more efficient circuitry and power management, a separate DC circuit to serve DC-powered appliances, and use of energy-harvesting sensors and controls in place of grid-powered components.