Certain factors are examined that contribute to the utilization of middle and high school facilities in the planning stage in the School District of Philadelphia. The study addresses itself to certain factors related to the methods of rostering schools which affect utilization of facilities in an urban area. A suggested program is developed outlining certain time allocations for various subject matter areas. These time allocations are projected into space needs, which are then compared to those of presently planned facilities. Based on analyses of time, space, capacities and program, several conclusions are made concerning the utilization of school facilities. A brief bibliography is included. (FS)