Emergency Egress Openings

NC Department of Insurance
Office of the State Fire Marshal - Engineering Division
1202 Mail Service Center, Raleigh, NC 27699-1202
919-661-5880
Emergency Escape and Rescue Opening Minimum Size
Code: 2006 Residential Code Date: October 1, 2007
Section: R310.1.1

Question:
What is the difference in the 4.0 square feet minimum net clear opening requirement and the minimum glass area requirement for emergency escape and rescue openings?

Answer:
The 4.0 square feet minimum net clear opening refers to the opening required when the sash is in the fully open position. This opening is expected to be used by the occupant for emergency escape.
The 5.0 and 5.7 minimum glass area requirement is the size of the window opening when all the sashes are removed. This opening size is based on the minimum required opening for a rescue worker to enter and remove an occupant. Also it expected that the rescue worker has the equipment required to knock the sash(s) out for access. The 5.7 square feet opening size for the second and third floors is to account for the additional area needed to dismount a ladder and enter the opening.

Keywords:
Fireman, firemen, glazing