Hoyts Cinemas, Philadelphia, PA.Exterior view at night. Architect:J.K. Roller Architects

Bathroom Interior. Toilet partitions separate public sink areas and private toilet areas in theater rest rooms.

Public rest room design must interpret code restrictions, as they relate to creating the ideal layout for men's and women' facilities. In theaters, which are classified as assembly use, architects must meet codes for all public spaces. Design factors drive the numbers of toilet partitions required. The code, rather than the client or the architect, determines the number of individual enclosed water closets in rest room design.

"Rest room use occurs primarily upon arriving at the theater or leaving after a movie is over. With this in mind, toilet rooms are located adjacent to the lobby, and in the most likely path of travel when exiting the building. Time factors into rest room use, as women often require more time than men. The number of water closets provided should address these peak demands," said Paul Georges, AIA, of J.K. Roller Architects, Philadelphia, Pennsylvania.

While some designers may believe that water closet ratios should be higher, such as twice as many water closets for women than for men, the code establishes criteria to calculate these requirements. In the design for assembly occupancies A-1, the International Building Code (IBC) states that for every 125 male occupants, one water closet, or enclosed partitioned toilet fixture, should be provided. The requirement is increased to one water closet for every 65 female occupants.

For example, consider a movie theater designed with a total of 2,000 seats. When divided equally, 1,000 occupants count for the men's room calculations and 1,000 for women. In the men's category, for every 125 of 1,000 occupants, one water closet is required, for a total of eight toilet fixtures. For women, every 65 of 1,000 occupants requires one water closet, for a total of 16 fixtures. The IBC allows up to two-thirds of the required water closets for men to be substituted with urinals, which are typically screened.

When designing for the numbers, the 2 to 1 ratio method isn't the rule. "Prior to the adoption of IBC, the Pennsylvania Code recognized the delays women faced with the use of rest room facilities in public places," said Georges. The Rest Room Equity Act of 1990 required that the toilet fixture count for women be a minimum of twice the amount of fixtures for men. This requirement was commonly referred to as "potty parity." With the adoption of IBC, depending on the actual occupant count, the fixture ratio can be less strict.