We're working on a vacation home in a ski resort seeking LEED for Homes certification. The home is expected to be used only during the winter season, and only for approximately 30 days a year. The project will have a low-impact hydropower that supplies all electric energy during the occupied Winter season. Natural gas will be used for heating. The low-impact hydropower lowers its electrical supply significantly during the first 3 summer months of the year.

Since the house will only be occupied during the Winter months, we would like to confirm whether the energy model required for the “Annuel Energy Use” can only consider the months where occupancy of the house is expected, or how the model should consider those months where the house is expected to be empty?

This will affect the energy savings result because the low-impact hydropower can only function during winter/spring seasons due to the available water flow during dry seasons.