Stairs Count Towards the Square Footage of the First Floor
When a single-family house is measured for an appraisal, it is measured from the outside.
This means that the square footage of the stairs (if there are any) is included in the measurements for the first story of the home.
The Stairs Don’t Get Counted Twice
If the house has more than one level, the second level is usually measured from the inside.
The appraiser adjusts for the wall thicknesses in his measurements to account for measuring from the inside (and not the outside).
When the second story is measured, frequently from the inside, the air space above the stairs is not included in the square footage of the second story.