There are plenty of reasons you might want to know how to calculate the square feet of a house, whether you’re looking to sell a property, dispute a high tax assessment or renovate to add more space. Square footage also matters in real estate deals that involve a mortgage, for similar reasons. The lender will want that info to verify what the property is worth.
What is Included
Main living spaces make up the bulk of a home’s square footage, including the kitchen, the living room, the dining room, bedrooms, and bathrooms. Stairways and hallways are also included, although these spaces are not as easy to measure as square rooms.
Other areas, like finished basements and attics, or enclosed porches, may or may not count as living space (and therefore, square footage). It all depends on your local regulations and practices. We’ll dive into details on this later.
“In the city of Chicago, we see a difference in the way square footage is calculated in the city versus the suburbs,” says explains top-selling Chicago-based real estate agent Scott Curcio. “For example, in the city, we generally count basement square footage as part of the overall square footage of a home. However, in certain suburban areas, they will not count it because they’re below grade.”
What to Leave Out
A good rule of thumb to ensure you’re taking proper measurements is to exclude space you can’t walk on or live in. These types of spaces do not count as “gross living area.”
“Someone might think, ‘If I get the measurement of my first floor and I have a two-story house, I just multiply that by two,’” says Marlon Day, senior director of Quest Valuation & Advisors in Atlanta. However, if that first floor includes a two-story foyer, you can’t count the non-usable space.
Here’s the deal with square footage gray areas
These are the top 10 gray areas that may or may not be counted in your home’s square footage total.
Unfinished: If your basement is unfinished (with exposed studs, cement, unpainted or plastered drywall, etc.), then it does not count towards your home’s square footage. You may, however, include the size of the basement in your listing description.
Finished: For a basement to increase a home’s square footage, it must meet certain criteria to be considered livable space, and such criteria can vary between states. Your local county assessor’s office determines whether appraisers can choose what is considered square footage toward a home’s Gross Living Area. Below are some of the most common criteria a basement may have to meet to be included in your home’s total square footage:
- A portion of the basement is above-ground – Basements that are 100% below ground usually do not count towards the square footage of a house.
- The basement is finished – Flooring, walls, lighting, and other features must be similar to the main living areas of a house
- The basement is heated and conditioned. You cannot use a space heater to heat up a basement.
- The basement has legal ingress or egress – To account for safety, a legal escape point is necessary in case a fire breaks out. This could be an egress window or walkout door that leads to the outside.
Get in touch with a real estate agent or appraiser to best understand if your basement can be counted towards the square footage of your home.
The square footage of a finished basement that is below grade, meaning underground, adds less value than the square footage of above-grade living space.
So if your home is 2,000 square feet, and you have an additional 1,000 square-foot finished basement, you cannot claim to have a 3,000 square-foot home if your local area values basement spaces at a lower dollar amount than the rest of the house.
In this instance, you would list your home at 2,000 square feet and then include the additional 1,000 square feet of living space in your finished basement in the listing notes.
“Regular garages for parking cars are never included in the living area,” explains Matt Harmon a North Carolina-based, state-certified property appraiser. “However, if they have finished walls, floors, ceilings — and are adequately heated by a permanently installed heat source — then they would meet the criteria for living area. Typically, when this is done, the sliding garage door is either removed or covered by a finished sheetrock wall.”
Closets are always included in your home’s square footage, as long as their construction meets your state’s square footage guidelines.
Bathrooms are also always included in your home’s square footage if they meet the minimum requirements. For example, a half-bathroom in your free-standing garage cannot be counted because it is not attached to the main house.
In some states, a finished basement bathroom may not count if it’s in an unfinished basement that separates it from the rest of the house.
Stairs that are finished and connected to the living area count towards your home’s square footage.
“In North Carolina, stairs are included in the floor they descend from as well as the floor they descend to, not to exceed the opening in the floor on the upper level,” Harmon adds.
- Covered porches and sunrooms
Open-air, covered porches never add to your home’s square footage, even if they are elevated to the same level as the rest of the house by the foundation. Screened-in porches do not qualify as living spaces either.
Four-season sunrooms count towards the total square footage. These sunrooms should have a built-in heat source and point of connection to the main living area.
- Guesthouses and accessory dwelling units
Guesthouses or accessory dwelling units (ADUs) that are completely detached from the primary residence cannot be counted within the overall total of the main home’s square footage. Guesthouses that are attached to the primary residence in a way that makes them accessible from the main home can be counted in the overall square footage, even if the guest home has its own entrance.
Like open-air porches, patios are not indoor living spaces, so you can’t include them in your home’s square footage.
Unfinished: An unfinished attic does not add to the total square footage.
Finished: Whether or not your finished attic adds square footage depends on the room’s design and your area’s customs.
“In our market area, finished attics that meet the criteria for a living area are included and counted as normal second or third-floor square footage,” advises Harmon.
Most rooms must legally have a ceiling height of at least seven feet to count as living space. Attics often have sloped ceilings thanks to the roof, so only a portion of the room can be counted towards your square footage.
According to the North Carolina Real Estate Commission’s Residential Square Footage Guidelines, “you may also include a living area the portion of the room with a ceiling height of at least five feet if at least one-half of the finished area of the room has a ceiling height of at least seven feet.”
In other states, you cannot count an attic toward your square footage if the ceiling height falls below seven feet. That’s why it’s best to consult a local real estate agent or appraiser who knows your area’s guidelines to determine if your space adds to the square footage.
Open-air balconies are never included in your home’s overall square footage.