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Postsecondary Education

NCES 2006-160
May 2006

3.2.2 Net Assignable Area (Net Assignable Square Feet—NASF)

(See figure 3-3)

  1. Definition. The sum of all areas on all floors of a building assigned to, or available for assignment to, an occupant or specific use.
  2. Basis for Measurement. Net Assignable Area is computed by physically measuring or scaling measurements from the inside faces of surfaces that form the boundaries of the designated areas. Exclude areas having less than a 3-foot clear ceiling height unless the criteria of a separate structure are met. (See section 2.3, What to Include in a Building Inventory.)

    Measured in terms of Net Assignable Square Feet (NASF),

    NASF = Sum of Areas Designated by the 10 Assignable Major Space Use Categories

  3. Description. Included should be space subdivisions of the 10 major space use categories for assignable space—classrooms, labs, offices, study facilities, special use, general use, support, health care, residential, and unclassified—that are used to accomplish the institution’s mission.
  4. Limitations. Deductions should not be made for necessary building columns and projections. These small areas are excluded as they represent an insignificant percentage of the total area of an average-sized space. Capturing their area would be unduly burdensome relative to the very small contribution they would make toward precision. Areas defined as building service, circulation, mechanical, and structural should not be included.

Figure 3-3. Net Assignable Area of a building by floor

Figure 3-3. Net Assignable Area of a building by floor