Contains requirements intended to encourage the use and reuse of existing buildings. The scope covers repair, alteration, addition and change of occupancy for existing buildings and historic buildings, while achieving appropriate levels of safety without requiring full compliance with the new construction requirements contained in the other I-Codes.
Changes in this edition include:

Climate-appropriate alternative added for building located in Tropical Zones.
In the residential providions, the inclusion of the Energy Rating Index Compliance Alternative as another compliance path adds more flexibility to the IECC.
Separate Chapters dealing with existing buildings were created in both IECC-Commercial and Residential Provisions