How to Measure Your Home’s Square Footage

One of the most confusing and misleading metrics in real estate is area — the “size” of a house.

Like most aspects of owning or purchasing a house, measuring the square footage of a home is complicated. There’s no established standard for measuring a residential property, and everyone seems to measure square footage differently. But if you get it wrong, it can affect your home’s value.

There’s no need to be nervous about calculating your home’s square footage, however. Let’s look at how easy it actually is to measure a home’s square footage accurately.

Gross living area

For most people, the gross floor area or gross living area (GLA) of a home is what they’re thinking when they hear “square footage.”

Here’s how to calculate your GLA:

1. Draw a floor plan of the interior of the home, drawing each floor separately — a simple sketch will do.
2. Break the home into measurable rectangles (such as bedrooms and hallways).
3. Don’t include unfinished areas, including patios, porches, and exterior staircases.
4. Calculate the area of each rectangle by multiplying its length by its width.
5. The sum of all these rectangles is the square footage of the home.

What to leave in (and take out of) the square footage

But, of course, it’s not that simple.

Many standards do not count basements (even if they’re finished) in overall square footage. Either way, make sure to measure the basement’s square footage for your records — you can still include it in any future property listings.

Conversely, finished attic space that’s fit for habitation and boasts at least seven feet of clearance should be included in your GLA. The same is true for any additional stories in the house.

For example, suppose you’re describing a two-story home with a 1,500-square-foot first floor, 1,000-square-foot second floor, and 800-square-foot finished attic. You could list it as 3,300 square feet with 1,000 square feet of unfinished basement and a 600-foot garage. But to describe it as a 4,900-square-foot house would mislead potential buyers about the size, and unfairly boost the property’s value.

Discrepancies in measurement

Because square footage is so vital in appraising a home, it’s important to pay close attention to what is being measured.

Some sellers may include an unfinished basement in their square footage, giving you an inaccurate picture of the livable portion of the home.

And architects and appraisers often calculate square footage by using exterior walls, which may conflict with a property’s GLA figure.

Regardless of how you measure your square footage, be transparent when selling, and diligent when buying.

If you claim that your home is 2,000 square feet based on your builder’s floor plans, and a buyer’s appraiser brings back a figure of 1,600, you could lose the sale or need to lower your price.

Similarly, as a buyer, make sure to do your research and get an independent square footage to ensure you’re getting what you pay for.