Analysis of Capacity
The capacity of a school reflects how many students a school is designed to serve. There are various methodologies that exist to calculate capacity, each with its advantages and disadvantages.
- Design capacity is typically defined as the capacity of a facility as it was designed. One benefit of this approach is that two schools with the same number of classrooms will have the same capacity as one another. Design capacity is also enduring and consistent, not subject to shifts from year-to-year, or even within a school year. However, it may not accurately reflect the space constraints a school is experiencing at a given point in time based on the current programming of its building.
- Program capacity, an alternative method, evaluates school facilities based on how that facility is currently being used. The benefit of this approach is that it provides insight into the utilization of a building based on its current programming.
Design Capacity Method
Chicago Public Schools uses the design capacity method, calculating the utilization of each school in the district based on its enrollment and ideal capacity. CPS 20th day enrollment data is used in these calculations. The ideal capacity of a school is a formulaic calculation based on the number of classrooms, set number of students per classroom and several other factors that can vary from school to school. A school’s utilization, shown as a percentage, is the ratio of its actual enrollment to the ideal capacity of the school. The categories below are used to calculate and categorize the utilization of each school in the district:
- Type of school - Elementary vs high school
- Type of space - Permanent building vs temporary construction or leased facility
- Classroom use - Diverse learner cluster classroom, Pre-Kindergarten classroom or small classroom
- Co-located Schools - Two or more schools share one building or campus
Utilization informs facility needs such as additional capacity and identifies opportunities for new programs and modifications based on available space in existing buildings as well as decisions related to new construction projects. In addition to the total number of classrooms and ideal capacity, space use for permanent buildings, modular buildings, lease spaces, and other information is reviewed when consolidation, new construction and demolition are being considered.