R310.2.1

Section R310.2.1 is titled 'Minimum opening area' and covers the requirements for the dimensions and operation of an emergency escape and rescue opening. The purpose of this section is to require designated emergency escape and rescue openings to be sized so that they are fairly easily used as an alternative to exit the dwelling, or for firemen with airtanks to enter the dwelling, in the event that primary egress paths are blocked. It also requires that dimensions are obtained by normal operation of the opening. Buttons, slides, clips, etc., that are commonly built into openings to allow for cleaning or repair, may not be used to obtain the dimensions required by this section.

The model shows several windows (which are not grade floor or below-grade openings per the exception to this section), some of which meet the dimensions of this section, and others that don't (which display the non-compliant dimension). The inspector should be checking for adequately framed opening sizes during the framing inspection (which is often done before openings have even been delivered to the construction site).