Short answer
Short answer
No. It is reported separately.
No, not in the ANSI Z765 total. A basement is below grade, so it is reported as a separate number, even when it is finished.
Why
If any part of a level is below the ground, the whole level counts as below grade. That is why a basement never adds to the gross living area, however well it is finished.
Exceptions
- Walk-out basements
- Still below grade when part of the level is below the ground.
- The floor above
- Still above grade. Only the basement level itself is below grade, not the floor on top of it.
- Listing services
- Many show finished basement area on a separate line.
- Appraisals
- Below-grade area is reported next to the GLA, not in it.
Example
Figure 1. Main floor: 1,400 sq ft counts. Basement: 1,000 sq ft is shown on its own line.
| Area | Sq ft | Under ANSI Z765 |
|---|---|---|
| Main floor | 1,400 | Counts toward the GLA |
| Basement | 1,000 | Reported separately |
Check your listing service
Some let you add finished basement area to the listing, on its own line.
Source and version
The rule comes from ANSI Z765-2021, Square Footage: Method for Calculating (Home Innovation Research Labs), in our own words. Source checked on September 24, 2026; this page checked on October 2, 2026.