Square Footage

Square footage (or gross living area) is the total finished, livable floor space in a home measured in square feet — and getting it wrong can mean overpaying by tens of thousands of dollars.

How It’s Measured

Appraisers measure the exterior dimensions of each floor and calculate the total area. Only heated, finished space above grade counts toward gross living area (GLA). That means your finished basement doesn’t count in most markets, even if it has a bedroom, bathroom, and home theater. Garages don’t count. Unfinished attics don’t count. Covered porches don’t count.

The standard is ANSI Z765, which most appraisers follow. But here’s the problem: not everyone follows it. Some MLS listings use county tax records (often inaccurate). Some include the finished basement. Some measure interior walls instead of exterior. A home listed at 2,400 sq ft might be 2,100 sq ft by ANSI standards.

Why It Matters Financially

If comparable homes sell for $200/sq ft and you think you’re buying 2,400 sq ft, you’d value the home at $480,000. But if the actual GLA is 2,100 sq ft, the value is $420,000. That’s a $60,000 difference based on a measuring error. Appraisers catch these discrepancies, but by then you’ve already made an offer and paid for an inspection.

Protecting Yourself

Don’t trust MLS square footage. It comes from the seller or agent, not an independent measurement. Your appraiser will measure independently, and their number is what the lender uses. If you suspect a listing is overstating square footage, ask the seller for the source — tax records, blueprints, or previous appraisal. The buying guide covers how to evaluate listing details critically before making an offer.