News & Media
Digital house model
Getty Images/Viaframe

How Do You Calculate a Home’s Square Footage?

No law mandates square-footage calculations, and while a national group offers guidelines, a home can be larger or smaller than the numbers listed by the county.

SEATTLE – While no laws govern a process for determining a home’s square footage, the American National Standards Institute offers guidelines to calculate it, which are largely considered the standard.

But discrepancies still exist. For example, some MLSs report all finished and unfinished square footage of a house as one number.

Since many buyers consider a home’s size important, they or their agents may need to determine what was included in the listing’s determination of the square footage of a home.

“Since square footage is used to determine a home’s market value, it can matter a lot,” according to a guide on the topic posted on Redfin’s blog. “When it comes time for you to sell, 400 fewer feet in measurement can impact the price you’ll get, particularly in a buyer’s market.”

There are some nuances to what is included and what is not. In general, below-grade spaces such as basements don’t usually count toward a home’s square footage. Even a finished basement is not usually counted toward a home’s gross living area. But it can be noted separately in the listing’s total area.

Also, garages, pool houses, guest houses or any rooms that require a person to leave the finished area of the main house aren’t usually counted either.

Covered, enclosed porches can be included as long as they use the same heating system as the rest of the house. Also, the finished attic square footage can be included as long as it has at least seven feet of clearance.

To check on the square footage, refer to a city’s building department records. But note that some unpermitted remodeling may not be reflected even in the records, so they aren’t always accurate either.

Source: “How to Easily Check the Square Feet of Your House,” Redfin Blog (March 10, 2020)

© Copyright 2020 INFORMATION INC., Bethesda, MD (301) 215-4688