Roof Type and Orientation
Roof Type has a significant impact on your Solar Panels Performance especially when Panels are aligned with roof angle. In that case Solar Panels Inclination toward sun can't be optimised for peak annual or seasonal performance. Flat Roof offer the option of optimising solar panel inclination and azimuth for best performance
Living Area (Square Footage)
The bigger the living area the higher Domestic Hot Water demand is. More Square Footage means more Bathrooms, Showers, occupants, etc....