The accuracy of the building heat loss and heat gain assessment is heavily dependent on a thorough evaluation of the condition of building enclosure. The evaluation should include the following items:

• Exposed above grade walls and basement walls (area, type, thickness, insulation, etc.)
• Windows, doors, and skylights (area, type, thickness, air sealing, direction, etc.)
• Ceilings and roof (area, type, thickness, insulation, etc.)
• Foundation type and insulation