Residential Square Footage Guidelines
From the North Carolina Real Estate Commission

The following guidelines and accompanying illustrations are designed to assist you in measuring, calculating and reporting the living area contained in detached and attached single-family residential buildings. At a minimum, information concerning square footage should include the amount of living area in the dwelling.  When reporting square footage, you should carefully follow these Guidelines.

Living Area Criteria

Living area (sometimes referred to as "heated living area" or "heated square footage") is space that is intended for human occupancy and is:

  1. Heated by a conventional heating system or systems (forced air, radiant, solar, etc.) that are permanently installed in the dwelling - not a portable heater - which generates heat sufficient to make the space suitable for year-round occupancy;
  2. Finished, with walls, floors and ceilings of materials generally accepted for interior construction (e.g., painted drywall/sheet rock or panelled walls, carpeted or hardwood flooring, etc.) and with a ceiling height of at least seven feet, except under beams, ducts, etc. where the height must be at least six feet four inches [Note: In rooms with sloped ceilings (e.g., finished attics, bonus rooms, etc.) you may also include as 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.]; and
  3. Directly accessible from other living area (through a door or by a heated hallway or stairway).

Real estate appraisers and lenders generally adhere to more detailed criteria in arriving at the living area or "gross living area" of residential dwellings. This normally includes distinguishing "above-grade" from "below-grade" area, which is also required by many multiple listing services. "Above-Grade" is defined as space on any level of a dwelling which has living area and no earth adjacent to any exterior wall on that level. "Below-Grade" is space on any level which has living area, is accessible by interior stairs, and has earth adjacent to any exterior wall on that level. If earth is adjacent to any portion of a wall, the entire level is considered "below-grade." Space that is "at" or "on grade" is considered "above-grade."

While you are encouraged to provide the most complete information available about properties offered for sale, the Guidelines recognize that the separate reporting of "above-grade" and "below-grade" area can be impractical in the advertising and marketing of homes. For this reason, you may report the square footage of the dwelling as the total "living area" without a separate distinction between "above-grade" and "below-grade" areas.

Determining whether an area is considered living area can sometimes be confusing. Finished rooms used for general living (living room, dining room, kitchen, den, bedrooms, etc.) are normally included in living area. For other areas in the dwelling, the determination may not be so easy. For example, the following areas are considered living area if they meet the criteria (i.e., heated, finished, directly accessible from living area):

Please note in the special remarks section of the listing web submission and advise purchasers of any space that does not meet the criteria for living area but which contributes to the value of the dwelling; for example, unfinished basements, unfinished attics (with permanent stairs), unfinished bonus rooms, shops, decks, balconies, porches, garages and carports.

Helpful Hints

Concealed in the walls of nearly all residential construction are pipes, ducts, chases, returns, etc. necessary to support the structure's mechanical systems. Although they may occupy living area, to avoid excessive detail, do not deduct the space from the living area.

When measuring and reporting the living area of homes, be alert to any remodeling, room additions (e.g., an enclosed porch) or other structural modifications to assure that the space meets all the criteria for living area. Pay particular attention to the heating criteria, because the heating system for the original structure may not be adequate for the increased square footage. Although agents are not required to determine the adequacy of heating systems, they should at least note whether there are heat vents, radiators or other heat outlets in the room before deciding whether to include space as living area.

When an area that is not part of the living area (e.g., a garage) shares a common wall with the living area, treat the common wall as the exterior wall for the living area; therefore, the measurements for the living area will include the thickness of the common wall, and the measurements for the other area will not.

Interior space that is open from the floor of one level to the ceiling of the next higher level is included in the square footage for the lower level only. However, any area occupied by interior balconies, lofts, etc. on the upper level or stairs that extend to the upper level is included in the square footage for the upper level.


The amount of living area and "other area" in dwellings is based upon exterior measurements. A one hundred-foot-long tape measure is recommended for use in measuring the exterior of dwellings, and a thirty-foot retractable tape for measuring interior and hard-to-reach spaces. A tape measure that indicates linear footage in "tenths of a foot" will greatly simplify your calculations. For best results, take a partner to assist you in measuring. But if you do not have someone to assist you, a screwdriver or other sharp tool can be used to secure the tape measure to the ground.

Begin at one corner of the dwelling and proceed with measuring each exterior wall. Round off your measurements to the nearest inch (or tenth-of-a-foot if your tape indicates footage in that manner). Make a sketch of the structure. Write down each measurement as you go, and record it on your sketch. A clipboard and graph paper are helpful in sketching the dwelling and recording the measurements. Measure living area and "other area," but identify them separately on your sketch. Look for offsets (portions of walls that "jut out"), and adjust for any "overlap" of exterior walls or "overhang" in upper levels.

When you cannot measure an exterior surface (such as in the case of attics and below-grade areas), measure the perimeter walls of the area from the inside of the dwelling. Remember to add six inches for each exterior wall and interior wall that you encounter in order to arrive at the exterior dimensions.

Measure all sides of the dwelling, making sure that the overall lengths of the front and rear sides are equal, as well as the ends. Then inspect the interior of the dwelling to identify spaces which cannot be included in living area. You may also find it helpful to take several photographs of the dwelling for later use when you return to your office.

Calculating Square Footage

From your sketch of the dwelling, identify and separate living area from "other area." If your measurements are in inches (rather than tenths-of-a-foot), convert your figures to a decimal as follows:

1" = .10 ft. 7" = .60 ft.
2" = .20 ft. 8" = .70 ft.
3" = .25 ft. 9" = .75 ft.
4" = .30 ft 10" = .80 ft.
5" = .40 ft. 11" = .90 ft.
6" = .50 ft. 12" = 1.00 ft.

Calculate the living area (and other area) by multiplying the length times the width of each rectangular space. Then add your subtotals and round off your figure for total square footage to the nearest square foot. Double-check your calculations. When in doubt, recheck them and, if necessary, re-measure the house.

Attached Dwellings

When measuring an "attached" single-family home (e.g., townhouse, duplex, condominium, etc.), use the same techniques just described. If there is a common wall, measure to the inside surface of the wall and add six inches. [Note: In the case of condominiums do not include the thickness of exterior or common walls.] Do not include any "common areas" (exterior hallways, stairways, etc.) in your calculations.

Proposed Construction

For proposed construction, your square footage calculations will be based upon dimensions described in blueprints and building plans. When reporting the projected square footage, be careful to disclose that you have calculated the square footage based upon plan dimensions. Therefore, the square footage may differ in the completed structure. Do not rely on any calculations printed on the plans.

The information above is taken directly from the North Carolina Real Estate Commission website.  Please Click Here for the entire Guidelines.