Lines 1, 2, and 3 of both the Standard and Optional Methods for load calculations are used to calculate which loads (in order they are listed)? Line 1 is used to only calculate the surface area of the dwelling unit, 2 and 3 are used for lighting and receptacles loads. Appliances, receptacles and heating and cooling loads. Lighting and receptacle, small appliance and laundry loads. Kitchens, bathrooms and bedrooms.