How many people can I seat?
As you might suspect, I hear this a question a lot from coaches, school officials, architects and designers. The answer can vary greatly based on the available space presented by the building conditions, the local building codes (where the project is located), the requirements of ADA (in Texas this is determined by the Texas Department of Licensing and Regulations) and the Life Safety Code which is part of the National Fire Protection Association guidelines found in chapter 102 (NFPA 102). Each of these can have a governing effect on the final seat count.
But first, we need to define some common terms and guidelines used by the bleacher manufacturer’s.
A. Gross Seats
B. Net Seats
Definitions:
Gross Seats. The manufacturers use this term to define the maximum number of seating spaces available on a bank of gym bleachers. This would be the maximum possible amount of seats in the available length times the number of seating rows. Or length times number of rows divided by 1.5 and rounded down. For example: 87 feet x 8 rows= 696 divided by 1.5= 464 Gross Seats.
Net Seats. The net seat count is the actual number of actual seat spaces available for use. To determine net seats, first you would need the gross seat count minus the seats lost to aisles and ADA spaces and building conditions (i.e. wall columns that protrude into the bleachers). Building codes, Life Safety Codes and ADA codes all factor into the final or net seat count. In other words how many aisles are required? How wide are the required aisles to be? How many ADA spaces are required? For Example: In the bank size illustration above the required number of aisles to provide ingress and egress extending to top seating row would be 3 aisles. Each aisles would be 4’ 6” wide or the loss of 3 seats per row, per aisle.
There are factors that can have an impact such as Row Spacing, Row Rise, Seat Depth and Clear Space, but for the most part the number of aisles, width of aisles and number of ADA spaces required will be the most common factors to consider.
Rule of Thumb Estimating Shortcut
To achieve the true net seats you will need to know the local building code, the ADA requirements and building conditions. However a good rule of thumb for estimating the net seats is reducing the gross seats by 20%. In the example above 464 gross seats less 20%= 371 net seats.
I hope this info is helpful.