Enrollment
Capacity
Since school utilization rates are used to determine overcrowding
and underutilization, it is important to understand the term enrollment
capacity. It describes the maximum number of students that a
school building can satisfactorily accommodate at one time for the
particular educational program and curriculum offered. Typically,
enrollment capacity is guided by state law, teacher contracts, and
the classroom assignments of the principal. Factors that determine
enrollment capacity are the number of classrooms in a school and
the number of students who can be assigned to each classroom. The
number of students assignable to a classroom varies by grade level
and by the type of instruction being offered. For example, high
school classrooms typically are designed to accommodate more students
than elementary school classrooms. Also, fewer students would be
assigned to a science lab than to a social studies class.
Enrollment capacity is also calculated differently in different
types of schools. In a high school, both basic classrooms and specialty
instructional spaces (such as art or music rooms) are counted toward
capacity because regular classrooms are not left unoccupied while
students get art or music instruction. Thus the formula for determining
secondary school capacity is the sum of capacity for each type and
number of classrooms multiplied by an optional utilization rate,
which may range from 75 percent to 90 percent. An optional utilization
rate recognizes the impossibility of scheduling classes so as to
fully utilize every classroom every period. For example, an advanced
science classroom may be able to accommodate 20 students, but there
may be only 16 students in the 5th period class. Even if some other
classes are overcapacity, the actual school utilization rate is
never over 100 percent.
Enrollment capacity for a secondary school is calculated as the
sum of the standard class size assigned to each type of classroom
in the school times the number of classrooms of this type. Thus
the capacity of two identical school buildings could be different
if they offer different types of programs or are subject to different
capacity limitations set by state law or teacher contracts. The
calculation of secondary school capacity is illustrated by Formula
4.
Formula
4 
Secondary
School Enrollment Capacity


Secondary
School Capacity = 
Sum of (Number
of all classrooms
X Students assignable to each type of classroom)
X Optional utilization rate 

In an elementary school, specialty instructional spaces are not
counted in the calculation of capacity space since regular classrooms
remain empty while classes are receiving instruction in the art
room or music room. Enrollment capacity then is based on the standard
class size assignable to each type of basic classroom in the school
(for example, a prekindergarten room will have fewer students assignable
to it than a 6th grade classroom, regardless of the rooms' actual
sizes), not counting specialized classrooms. Moreover, a utilization
rate is not applied. The calculation of enrollment capacity for
an elementary school is illustrated by Formula 5.
Formula
5 
Elementary
School Enrollment Capacity


Elementary
School Capacity = 
Sum of (Number
of basic classrooms
X Students assignable to each type of classroom) 

Instructional spaces that generate capacity for enrollment are
considered capacity space while all other rooms and spaces within
a school building are considered noncapacity, or unassigned, space.
Even though noncapacity space—including hallways, stairwells, cafeterias,
playgrounds, parking lots, teacher work areas, storage rooms, restrooms,
etc.—is not considered in the determination of enrollment capacity,
it cannot be ignored when determining the adequacy of a facility.
For example, the sizes of the existing cafeteria and hallways need
to be considered when adding a wing with new classroom space.
Density
Factor
Density factors are another way of comparing schools for overcrowding
or underutilization. While utilization rates compare enrollment
capacity to actual enrollment, the density factor compares the standard
gross square feet of building space per student, as established
by an educational specification space standard, to the actual amount
of gross square feet of building space per student. There are no
universal standards for how much space should be allotted for each
student in a school. Rather, space standards vary according to the
instructional program, school design, grade levels, and budget.
The density factor is calculated as in Formula 6.
Formula
6 
Density
Factor


Density Factor =

Standard
Gross Square Feet per Student
Actual Gross Square Feet per Student 


If school district or state department of education guidelines
indicate that a standard elementary school facility requires 115
gross square feet per student, an elementary school with 78 gross
square feet of space per student has a density factor of 1.47. Another
elementary school of the same size with fewer students, resulting
in 140 gross square feet per student, would have a density factor
of .82. A density factor of 1 indicates that a school has the density
recommended in the guidelines.
Unassigned space that is not reflected in the calculation of enrollment
capacity is counted when calculating the density factor. For example,
one school may have 12 classrooms (each of which can accommodate
25 students), a lunchroom, and a main office adding up to a school
capacity of 300 students. Another school has 12 classrooms of the
same size (with 25 students assigned to each classroom), but also
has a music room, art room, library, parent resource center, and
main office. Both schools have an enrollment capacity of 300, but
the second school would be less crowded and would have a lower density
factor.
Calculation of Gross Square Feet per Student
A key measure in determining a school's density factor is the
gross square feet per student (GSF/student). This is the total square
footage of the school—including all instructional and noninstructional
interior spaces—divided by the number of students enrolled
at the school. The only spaces not included in this calculation
are those used by nonschool programs, such as a community health
clinic or offices for central administration staff. The calculation
of GSF per student is shown as Formula 7.
Formula
7 
Gross
Square Feet per Student

Gross Square Feet per Student =

Gross Square Footage of Building
Student Enrollment 


The GSF/student measure is particularly useful when more detailed
or reliable capacity information is unavailable. School districts
usually know the gross size of a school and always have the current
student enrollment. However, a shortcoming with this measure is
that schools of the same size vary tremendously in design. A school
built with an openplan design and a school with the doubleloaded
corridors, small classrooms, and few support spaces that were typical
of the 1950s could have the same gross square footage and the same
enrollment, but one could feel crowded and the other one not because
of how differently their space is used.