Step Outside to
Measure Square Footage

Question: Could you tell me exactly how the square footage of a house is calculated? Do I count closets, halls, stairs etc.? Do I measure the length and width from the inside or the outside, or should I measure each individual room from wall to wall? I know how to do the math, but I'm not sure where to measure from.

Sheldon: According to the National Association of Home Builders and the American National Standards Institute, square footage should include above- and below-grade space, measured from the exterior surface of your home's exterior walls.

In addition, the NAHB standards also include the following stipulations:

• Measure to the nearest inch or tenth of an inch, and report to the nearest whole square foot.
• Include only finished areas.
• Calculate and report above-grade and below-grade square footage separately. The standard does not provide for reporting "total square footage." A space is included in the below-grade total if any part is below the grade line.
• Stair treads are included. Floor openings are not included.
• Ceilings must be at least seven feet high except under stairs, beams, and sloping ceilings.
• Accessory apartments and other finished areas not within the house can be included if they are connected to the main house by finished hallways/stairways.
• Garages are not regarded as finished space, but can be calculated as unfinished square footage.

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Sheldon, Port Washington, Wis.

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