Laboratory testing is the typical way to verify that fenestration products meet specified structural design pressure (DP) criteria. However, engineering analysis can be a viable alternative when standard lab testing will not be sufficient. This article dives deeper into the Fenestration and Glazing Industry Alliance (FGIA)’s consensus-based process for engineering evaluation of structural integrity: AAMA 2502, Comparative Analysis Procedure for Window and Door Products—which is now approved as a reference standard in the International Building Code (IBC).