The ANSI-Z765 measurement standard (ANSI standard) is a guide created by US real estate industry participants for measuring residential single-family properties and required by Fannie Mae for loan agreements. The standard we offer is based on both the original ANSI standard rules as well as Fannie Mae interpretations of it. To make the calculations suitable for different regions and situations, the area inclusion change in the FP editor can be utilized.
The standard applies only to attached or detached single-family houses. As per Fannie Mae, the only difference in calculations when measuring apartment-style dwellings - the area occupied by exterior walls is excluded.
Note: Initially all properties calculated by this standard are assumed as residential houses; the property type can be changed to “apartment” after receiving the project.
Measurement Basis
Measurement start: Measurements are taken from the exterior finished surface of the outside walls (we assume the most common wall thickness: 6in), interior walls are included;
Note: As per Fannie Mae guidelines, for apartment-style dwelling area calculations exterior wall thickness is excluded. All other ANSI standard principles apply
GLA: gross living area by default includes all finished above-grade spaces of the main building
Finished area: has floors, walls and ceiling with similar quality finish suitable for occupancy and is suitable for year-round use (we assume garages, sheds and attics used as storage as unfinished)
Above-grade level: all walls of a level have to be completely above grade to qualify as above-grade, and this categorization applies to the whole level, not separate rooms (customer verification upon receiving project is important as we cannot always detect cases where the level is partially below grade)
Note: We recognize regional differences can occur when determining finished areas and/or above-grade levels. Our Floor Plan Editor allows changing room inclusion, e.g., from finished to unfinished and vice versa, and the Project Settings allow changing the grade level.
GLA Inclusions
Stairs & landing: stairs are included on the level they descend from insofar where the stair opening overlaps with the staircase
Free-standing pillars and half-walls: Included
Lift shafts & niches: Included
Voids (open to below): Excluded
Protrusions beyond the exterior wall: Excluded, unless they start at floor level and meet ceiling height requirements (typical protrusions: bay windows and chimneys).
Reduced Headroom
Standard ceiling height 7ft and more: Included
Headroom below 5ft: Excluded
Area below stairs: Included (regardless of headroom)
For reduced headroom zone calculations we regard each room separately. We deduct the areas that are not included in any case (below 5ft) and then weigh the reduced headroom area portion against the portion with standard ceiling height.
Below 7ft, but above 5ft (sloped ceilings):
If more than 50% of room area has a headroom between 5ft and 7ft, the entire room is not included in GLA (included in Non-Standard Finished).
If less than 50% of floor area has a headroom between 5ft and 7ft (standard ceiling height is dominant), the entire room area is included in GLA.
Below 7ft, but above 5ft (straight ceilings):
Included in Non-Standard Finished area category
Special circumstances
Unfinished areas next to finished: In case an unfinished room is next to a finished space (let’s say a garage next to a kitchen), the interior wall these rooms share becomes the “assumed” exterior wall for the purpose of GLA area calculations.
Non-standard finished areas: In some cases an area can technically meet all finished area criteria, but not be included in GLA due to reduced ceiling height. In such cases, these areas are included in the Non-Standard Finished area category as to not be excluded completely, as they are still livable areas.