Minnesota State Fire Code (MSFC requirements for emergency escape and rescue openings, otherwise known as egress windows, in sleeping rooms below the fourth story in residential occupancies (Group R and I-1) is broken down into three categories.

1. Existing occupancies when either: 
   1. Constructed after July 1,1972.
   2. Licensed by State of Minnesota.
   3. Used as transient lodging.
2. New occupancies with sleeping rooms on main floor (level of exit discharge).
3. New occupancies with sleeping rooms in basements or above the main floor.

Our staff participated in an egress window study at a major window manufacturer to determine the absolute minimum size that would be acceptable for occupants to safely escape and firefighters to enter for rescue in existing residential occupancies. The study led to an updated policy for licensed occupancies such as home daycares. This policy is now code language in the 2020 MSFC Section 1104.26. 

The minimum required opening for existing sleeping rooms on any level of the residence up to and including third floor is 4.5 square feet or 648 square inches. This PowerPoint will show how the measurements are taken to determine if the existing window opening complies with MSFC Section 1104.26. 

Window opening size not in compliance with MSFC Section 1104.26.2 shall be replaced with windows complying with the requirements for existing residential occupancies in MSFC Section 1104.26.6. In many cases a double hung or sliding window can be replaced with a casement insert and meet the requirements for egress windows.