There are 3 different credits on form 5695.
Under section 25C, the credit for energy efficient home improvements (windows, doors, insulation, heat pump) applies to any dwelling that is owned by the taxpayer AND used as the taxpayer's principal residence (main home).
However, also under section 25C, the energy efficient property credit (efficient furnace, air conditioning, boiler, water heater) can be applied to any dwelling that the taxpayer uses as a residence. It does not have to be your main residence and you don't have to own the dwelling.
Under section 25D, residential clean energy credit (solar, geothermal, wind, fuel cell, battery), the credit can be applied to a dwelling the taxpayer uses as a residence (solar, wind, geothermal, battery) or their main residence (fuel cell). The taxpayer does not have to own the home.
