Building Envelopes are the most difficult systems to predict for Section §179D. It is beneficial to keep these considerations in mind: Solar panels and wind turbines are not considered when modeling for §179D deductions. Only building systems are considered in the model. Exterior site lighting is not included in the model. Miscellaneous (receptacle) loads are removed from the building energy usage. When only modeling a single system (i.e.; lighting, HVAC, or envelope) the other systems are placed at ASHRAE 90.1-2001 baselines.* Occupancy/Equipment schedules are from California Title 24.