A Final Thought

Measuring Elementary School Capacity

What’s the capacity of an existing elementary school? That should not be difficult to answer but recently, working with a school district with 11 elementary schools, answering that question became a little sticky.

It started when I was handed a sheet naming each of the buildings and indicating its capacity. I was told that the state had produced those numbers, but not when or on what basis. The district was planning to reorganize from K-5 schools to K-8, and my assignment was to determine how many schools would be needed, and what their capacity would be if that were done.

My first question concerned class size policy. After all, if a district allows 30 students in a class, its capacity is going to be greater than another district with an identical school that caps class size at 22 or 25. In this case, the district had no set policy but wanted class size to average no more than 25 students.

My next question concerned district policy towards specialized spaces. During the Baby Boom of the 1960s and ‘70s, it was not unusual for districts to construct elementary schools with classrooms, a principal’s office, another office for the nurse and a multi-purpose room — period. Music was on a cart; art in a closet. Wealthy districts sometimes provided a library. Count the classrooms, multiply by 30 or 32, and you knew how many students could be crammed into an elementary school.

Today, few districts would accept such sparse accommodations. My client wanted a library in each elementary school, along with an art room and a music room. It also sets aside a full-size classroom in each building for special education support. So, if we were dealing with a 30-classroom building designed without a designated library, we had to take four existing classrooms and assign them for art, music, library and special education. Capacity had to be determined based on the use of 26 rooms to which students could be assigned. At an average 25 per room, the school’s capacity was 650. That’s easy. But there was more.

The district, dissatisfied with its current middle schools,
wanted to move to K-8 buildings, giving teachers and students a longer time together. But, to meet state mandates, students in grade 8 must have access to a science laboratory, turning at least one more existing classroom into a special room. So, as a K-8 school, the 30-classroom building noted above really has only 25 rooms in which to schedule regular classes. Capacity: 25 rooms by 25 students = 625.

There was still another wrinkle to consider. A child entering kindergarten in a K-8 school must be able to remain in that building for nine years and not be expected to jump back and forth between different buildings. In a K-5 school with 25 available classrooms, four sections could be formed for each grade, using 24 rooms, with one room unspecified.

In a K-8 school, only two sections of each grade can be formed, filling 18 rooms and leaving the use of seven rooms unspecified. Creating K-8 schools does not necessarily change the capacity but it does eliminate some flexibility. If only 18 rooms are used as regular classrooms, student enrollment would be limited to 450.

So, what is the capacity of that existing 30-classroom building? It depends on district policy (class size), the desire to provide designated rooms for music, art, computer science and other special uses, and providing accommodations for students with special needs. It also depends on the grade levels included.

There is one other factor not included above. All rooms are not created equal. The size of a room should be taken into consideration. A number of years ago, a researcher suggested that the capacity of an elementary school room should be calculated by taking the size of the room (square feet), subtracting 140 square feet from the total to allow space for the teacher’s desk and to move around, and divide the remaining space by 25, providing 25 square feet per student. Thus, in a 750 square foot room (25 x 30), subtract 140 for the teacher and divide the remainder (610) by 25 to get the maximum number of students (24) for that room.

Today, that would be pretty tight. A better measure might be to provide 150 square feet of teacher space and 30 square feet per student to allow for greater movement, the use of technology and small group and individual space. In that case, only 20 students would be assigned to a 750 square foot room.

So, what is the capacity of that existing elementary school? Not such an easy question to answer except you can be sure that it is less than it was when you went to school.

This article originally appeared in the issue of .

About the Author

Paul Abramson is education industry analyst for SP&M and president of Stanton Leggett & Associates, an educational facilities consulting firm based in Mamaroneck, N.Y. He was named CEPFI’s 2008 "Planner of the Year."