Any other penetrations through the exterior walls are air sealed. This can be done manually or with the aid of a setback thermostat. Room air conditioners, are sized properly and on timers. They only require about 30 minutes to cool and dehumidify a room, so there is no need to have them on if no one is home. Floor heat registers, baseboards, radiators, and return air grills are kept clear of obstructions like rugs, drapes, and furniture.
Kitchen appliances are in good working order, clean, and have tight-fitting seals.
The checklist can usually be completed from the attic hatch. If your home is a side or backsplit, there will be more will be more than one attic space. All penetrations into the attic, such as light fixtures, ceiling fans, plumbing stack, etc. are air sealed either from the attic side or ceiling side. You can check this by removing light fixture cover plates or by looking in the attic. Heating ducts that run through the attic are taped at the joints and insulated.