Update: Dealing with the following assertion:
"Theater style seats are not preferable, but if required they should not be touching or in any way interlocked together"
From Ron Coté, Principal Life Safety Engineer:Important Notice: This correspondence is not a Formal Interpretation issued pursuant to NFPA Regulations. Any opinion expressed is the personal opinion of the author and does not necessarily represent the official position of the NFPA or its Technical Committees. In addition, this correspondence is neither intended, nor should it be relied upon, to provide professional consultation or services.
Some of the meeting room / ball room / restaurant chair interlocks permit an adequate gap between seating surfaces to accommodate some degree of body spread. I expect chair manufacturers, who are aware both of the code requirements to secure chairs together in groups and of the increasing obesity problem, to make available interlocks that will provide even more space between chairs. The manufacturers will need to balance the new need presented by the obesity epidemic against the danger of having the interlocks protrude from the side of a chair when it is not locked to another chair.
In the 2012 edition of NFPA 101®, Life Safety Code®, the subject is addressed in 12.7.9.1 and 12.7.9.2 for new assembly occupancies (also in 13.7.9.1 and 13.7.9.2 for existing assembly occupancies – using the same text but different paragraph numbers). The text follows:
12.7.9.1 Secured Seating.
12.7.9.1.1 Seats in assembly occupancies accommodating more than 200 persons shall be securely fastened to the floor, except where fastened together in groups of not less than three and as permitted by 12.7.9.1.2 and 12.7.9.2.
12.7.9.1.2 Balcony and box seating areas that are separated from other areas by rails, guards, partial-height walls, or other physical barriers and have a maximum of 14 seats shall be exempt from the requirement of 12.7.9.1.1.
12.7.9.2 Unsecured Seating.
12.7.9.2.1 Seats not secured to the floor shall be permitted in restaurants, night clubs, and other occupancies where fastening seats to the floor might be impracticable.
12.7.9.2.2 Unsecured seats shall be permitted, provided that, in the area used for seating, excluding such areas as dance floors and stages, there is not more than one seat for each 15 ft2 (1.4 m2) of net floor area, and adequate aisles to reach exits are maintained at all times.
12.7.9.2.3 Seating diagrams shall be submitted for approval by the authority having jurisdiction to permit an increase in occupant load per 7.3.1.3.


- Two participants per each six foot table
- Three participants per each eight foot table
- Five participants per twelve foot table
- A maximum of six per sixty inch round table
- Seating without arm rests
- Seating that supports the lumbar
- Seating that is sufficient in both length and width to avoid circulation discomfort
- Seating that can adequately support weight for extended periods of time
- Alignment of the presentation area that allows for ease of viewing so that taller individuals do not need to be displaced and to allow for unobstructed views for other participants
- Frequent aisles with ample space to access without hindrance
- Theater style seats are not preferable, but if required they should not be touching or in any way interlocked together
- Accessibility via an elevator, escalator or located on the ground floor without steps required for access
- Ensure all pass-through doors and restrooms adhere to the Americans with Disabilities Act (ADA) guidelines with a minimum of 32 inches in width
- Confirm that hinged restroom doors do not swing into the clear floor space required to use any fixture as to not impede the use of sinks or toilets.
- Individual room thermostat control, not centrally controlled

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