A system generates an estimated floor area measurement of a building based on the calculated estimated total roof area of the roof of the building. This is based on a correlation between the size of the building roof and the size of the building. Typically, the floor area of a single full floor of the building is roughly the size of the roof of the building if the roof were flat with no slope. This in effect is turning the roof into a floor to generate estimated floor area. With additional adjustments to area measurements to account for multiple floors, roof overhang, wall width, internal building features such as walls and staircases, and/or obstructed views of the building in the aerial image(s), etc., an even more accurate floor area estimation may be generated.