Square Footage: How is it Measured?

It isn’t uncommon for me to get a call from buyers asking why the appraiser came up with a different square footage from what was shown on the MLS listing that they trusted when making their offer, or the square footage indicated on the county assessor’s website. It seems simple, right? Just measure all the spaces in the house, and there you have it. Unfortunately, how those spaces are measured depends on the person doing the measuring.

If you are getting an appraisal, the square footage your appraiser comes up with may be widely different from what the MLS listing said. Appraisers are to measure the “gross living area” (“GLA”) of a home. The GLA encompasses bedrooms, bathrooms, kitchens, dining rooms, living rooms - and any space that is finished with heating and ventilation. Therefore, it does not encompass decks or garages. Further, the American National Standard Institute, which provides the guidelines for measuring GLA requires that “living space” be above-grade. Therefore, a finished basement is not factored into GLA. Even if the basement is a walk-out, or partially above grade, appraisers are not supposed to factor it in. There are additional guidelines as well, which dictates that certain bedrooms may not be sizable enough to count as a living space, or an attic does not have a high enough ceiling to be considered living space. To know for sure how an appraiser came up with the square footage, they should be specifically asked.

Developers, on the other hand, are marketing a home and will count all kinds of space in their measurements potentially. They may count the square footage of decks, terraces, basements and even garage spaces. They want to show a big number in their marketing materials.

Assessor measurements are different still. As everyone in Illinois is well aware, property taxes are based, in large part, on the square footage of a home. But the assessor’s number could be vastly different from what is in the developer’s marketing materials, since the assessor does not count basement square footage – finished or unfinished. Per the Cook County Assessor, their office “calculates the square footage by measuring the exterior perimeter of the home. It is that measurement that your assessment is based upon, not what you might consider to be “living space”.”

And where does the square footage on the MLS come from? Chances are if you ask the realtor, they may have relied on any number of these things. Perhaps their seller had an old appraisal. Perhaps they went to the Assessor’s records. Or perhaps the Seller still had the developer’s plans from when they purchased, and the square footage came from that. Now, the MLS listings are supposed to indicate the source of the square footage, but there are options on the MLS allowing them to “estimate” the square footage.

The bottom line is you have to ask whoever did the measuring, how they reached the number. As a Seller, while you may want to market a high number of square feet to get people interested, if your buyer’s appraiser comes up with something lower, that could be a bargaining chip in trying to get the price reduced.

If you have questions about the square footage of your home or the home you want to buy, be sure to ask those questions. You are entitled to answers. Feel free to contact Kelly Anderson (847-705-7555 and kanderson@lavellelaw.com) at Lavelle Law with your questions.