For SDC E, the IRC contains provisions for reclassification of structures from SDC E to D2 (see IRC Section R301.2.2.1.2) under the following circumstances: Where the structure is in a SDC D region based on in the International Building Code maps, or All exterior braced wall panels are in the same vertical plane from foundation to roof, and Floors do not cantilever over exterior walls, and Building meets IRC Section R301.2.2.2.5 requirements for regularity For SDC E structures that do not meet these requirements, the prescriptive structural requirements of the IRC cannot be used and the IBC, or other referenced standards, must be used to design the structure.