What Counts as Square Footage in a House? A Practical Guide for Homeowners and Agents

Disclaimer: Our articles are written by a Licensed or Certified Residential Appraiser. This information is meant for educational or informational purposes only, and does not support or indicate an opinion of value for your home or property, nor does it provide any type of value indication for a lender, attorney, realtor, or any other individual or entity.

So, you just dropped $50K on a stunning finished basement—built-in bar, custom theater room, the works.

It has to count as square footage now, right?

Not so fast.

When it comes to appraisals and valuing your home, not all spaces are created equal.

In fact, what counts as square footage in a house—also known as gross living area (GLA)—follows very specific rules, and are often misunderstood by homeowners, agents, and even local assessors.

In this guide, we’ll break down what does (and doesn’t) count as official square footage in a house — according to appraisal standards.

Whether you’re preparing to sell, refinance, or just trying to understand your home’s value, here’s what you need to know.

whats included in a home's square footage cheat sheet

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What Does “Above Grade Living Area” Actually Mean?

Let’s start with a core concept: above grade living area.

“Grade” refers to the ground level around your home. So, above grade means any livable space that sits entirely above ground.

👉 If even part of a certain home level is below grade—as most basements are—it does not count as part of your home’s official square footage.

This is most likely one of the biggest misunderstandings in real estate.

A finished basement might be beautiful, but that doesn’t make it GLA.

What Counts as Square Footage in a House?

Appraisers typically follow the ANSI Z765-2021 standard for measuring residential properties.

Here’s what must be true for an area to count in your home’s square footage:

ANSI Requirements for Gross Living Area (GLA):

Completely above ground level (not partially below grade)
Permanently heated (no space heaters or seasonal systems)
Ceilings at least 7 feet high (6’4″ allowed under beams or ductwork)
Finished, enclosed, and directly connected to the main living area
Accessible from the interior of the home

Spaces Usually Included in a Home’s Square Footage:

Bedrooms, bathrooms, living rooms, kitchens
Finished and heated mudrooms or laundry rooms included within the main home
Hallways and closets
Built-in pantries
Finished attic spaces (if they meet height and access rules)
Open-concept areas with usable floor space

What Doesn’t Count as Square Footage in a House?

The following is a list of common spaces that do not count toward your home’s official square footage—even if they look great on a listing:

Basements – Any level that’s even partially below grade is excluded from GLA
Open-to-below spaces – Like two-story entryways or loft overlooks
Attics – Only counted if finished, with proper access and ceiling height
Enclosed porches/sunrooms – Must be finished, insulated, and permanently heated to qualify
Balconies – Not enclosed or usable as interior space
Garages – Not considered living area, even if finished or heated
Detached buildings – Like guesthouses or pool houses, unless connected and meeting GLA standards

📌 Important: County assessors or real estate agents sometimes include these in square footage, but appraisers won’t.

MLS data can also be unreliable.

Why It Matters: The Value of Accurate Square Footage

When selling or refinancing, above grade square footage is one feature that makes a big impact on the appraised value.

A 2,400 sq ft home will generally be worth more than a similar 2,000 sq ft home, assuming the extra 400 square feet qualifies under ANSI rules.

That’s why appraisers independently measure the home and don’t rely solely on public records, Zillow, or the MLS.

These sources often include unqualified or inaccurate square footage, which can mislead buyers and skew comps.

Real Estate Agents: Accurate Listings Mean Better Appraisals

If you’re an agent, it’s critical to represent square footage accurately in the MLS.

Overstating GLA by including basements, sunrooms, or partially finished areas can:

Create unrealistic buyer expectations
Lead to lower-than-expected appraisals
Delay closings or cause contract issues

💡 Pro tip: When in doubt, consult the ANSI guidelines—or better yet, ask an appraiser.

What About ADUs? Do They Count Toward a Home’s Square Footage?

Detached ADUs (Accessory Dwelling Units) do not count in the gross living area of the main home.

However, that doesn’t mean they have no contibuting value.

Appraisers consider ADUs as a separate improvement and determine their added value based on:

Their construction quality
Intended use
Market demand for similar amenities

If your ADU is attached, meets the ANSI criteria, and flows with the main home, it could be included in the total GLA—but that’s the exception, not the rule.

Not Everything Has to Be Square Footage to Be Valuable

A finished basement, studio above the garage, or detached ADU can still add real market value, even if not part of your official GLA.

Appraisers look at contributory value of all features, not just square footage measurements.

These other spaces often show up as bonus features that enhance livability and enjoyment of the home—even if they’re not technically included in its square footage.

Quick-Reference: What Counts as Square Footage in a House?

Use this simple checklist to figure out whether a space qualifies as GLA:

✅ Is the space entirely above grade?
✅ Is it finished and heated with a permanent system?
✅ Does it have ceilings 7’ or higher?
✅ Is it directly connected and accessible from the main house?

If the answer is yes to all four — it should most likely count in your home’s square footage.

For a deeper dive on appraisal requirements, consult the Fannie Mae Selling Guide or read through our blog on Appraisal Basics.

Frequently Asked Questions: What Counts as Square Footage in a House?

What counts as livable square footage?

Livable square footage (or Gross Living Area) includes finished, heated, and accessible spaces that are entirely above grade. These areas must have ceilings at least 7 feet high and be directly connected to the main part of the house.

Do stairs count as square footage?

Yes. If the stairs connect finished, above-grade living areas, both the stairs themselves and the space beneath them are included in the home’s square footage.

Does a finished attic count as square footage?

Only if it meets all ANSI standards: finished, permanently heated, accessible by a standard staircase, and has ceilings at least 7 feet high (or 6’4″ under beams or ductwork).

Does a covered porch count as square footage?

Not usually. Covered porches only count if they’re fully enclosed, finished, permanently heated, and built to the same quality as the rest of the home.

Are laundry rooms included in square footage?

Yes, if the laundry room is finished, heated, and located within the main, above-grade living space, it counts in the total square footage.

Do cabinets count in square footage?

Yes. Cabinets, countertops, and other built-in features in finished rooms are part of the usable floor area and are included in square footage calculations.

Are walls counted in square footage?

Yes. Appraisers measure Square footage from the exterior walls, so interior walls are included in total square footage.

Does a garage count as square footage?

No. Even if finished or heated, garages are not part of the gross living area and are excluded from square footage measurements.

What is the average square footage of a house?

In the U.S., the average new single-family home is around 2,400–2,600 square feet, but this varies by region, lot size, and style.

Who decides what counts as square footage in a house?

Appraisers use ANSI Z765-2021 guidelines to determine what qualifies as square footage. Their measurements are typically more accurate than public records or MLS listings.

Need clarification on what counts as square footage in your house?
Drop us a message—we’re happy to help.

Kimberly W

Kimberly has been a Certified Residential Appraiser in NY State since 2004. With a background in the mortgage industry and real estate sales, she brings a valuable perspective to buyers, sellers, and other industry professionals.

Aside from her professional role, she’s an entrepreneur, novice home flipper, and proud Mom of three.

FHA/USDA Certified | Member GSAR/NYSAR | Supervisory Appraiser

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