On Friday, January 19, 2018, CPS released new Utilization Review formula guidelines for calculating whether a school is considered “underutilized” (not enough students), “efficient” (the right number of students for the space available), or “overcrowded.”

The updated formula includes a change to the Efficiency Range used to calculate the point at which a school was considered too empty or too overcrowded.

As we discussed before the last round of school closings, the previous range of 80% – 120% indicated that CPS considered classrooms of less than 24 students as being underutilized and classrooms only overcrowded if they exceeded 36 students. You can revisit our explanation of the problems with the previous formula here. 

Here is what the CPS Space Utilization Formula looked like in 2011-2012 with Classroom Size limit as Ideal Enrollment.


The new formula changes the range to 70% -110%…not quite going all the way to our recommended range but in the right direction.

Since the maximum limit for elementary school classrooms in CPS is 28 and 31 (see our explanation previously), 30 needs to be the top of the range. It’s still being used by CPS as the ideal classroom size with more students than the ideal considered efficient midpoint.


The new formula is supposed to take into consideration rooms that have legally limited caps on attendance (such as self-contained classrooms) and special use rooms (Parent University spaces, for example). Also a positive development. You can see how the lack of acknowledgment of self-contained classrooms affected a special education cluster school, Trumbull Elementary, during the last school closings.


All of this should be a good thing…however, it seems that the data about the number of classrooms for many of the CPS schools have changed. Sometimes significantly. Even those buildings have not been changed or otherwise been physically altered since 2012.

Next up? Why have the facilities numbers that the formula is being applied to changed?


2 thoughts on “New Year… New CPS Utilization Formula

  1. Pingback: CPS Space Utilization Data changing? Part 2 | Apples 2 Apples in Chicago Public Schools

  2. Pingback: Space Utilization… then (2015) and now (2018) | Apples 2 Apples in Chicago Public Schools

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