An exterior building sketch that indicates dimensions and calculations that demonstrate how the estimate for gross living area is derived is required.
If the floor plan is atypical or functionally obsolete, thus limiting the market appeal for the property in comparison to competitive properties in the neighborhood, Fannie Mae requires a floor plan sketch that includes the interior walls.
For a unit in a condo or co-op project, the sketch of the unit must indicate interior perimeter unit dimensions rather than exterior building dimensions (dimensions and estimates for gross living area shown in the condo documents are acceptable).
For additional information, see B4-1.2-01, Appraisal Report Forms and Exhibits.