What is the maximum force required to open any door leaf manually in a means of egress for a new building?

The correct answer is 15 lbf, which aligns with the standards set forth by the NFPA and the accessibility guidelines under the Americans with Disabilities Act (ADA). These regulations emphasize that doors in a means of egress must be accessible to all individuals, including those with disabilities.

A maximum force of 15 pounds ensures that doors can be easily opened by individuals who may not have significant strength, promoting safety and accessibility during an emergency evacuation. This force requirement is crucial for maintaining a safe environment in buildings, especially as it limits the physical effort required, thus supporting quicker and more efficient evacuation routes. Meeting this standard contributes to the overall life safety design of a building, reinforcing the principle that egress pathways should be usable by the broadest range of people without undue stress or delay.

Any higher force requirement, such as 25 lbf or more, could hinder accessibility and potentially compromise safety during an emergency situation, thus contradicting the goals of life safety regulations.