Residential Existing Buildings The IECC has provided some guidance on how to treat existing residential buildings. This session is going to review the residential requirements of chapter 5 including topics for additions, alternations, repairs, and change of occupancy. All Audiences existing buildings,IECC,residential Related Videos 45:47 2024 IECC Sunrooms and Garages 1.01:03 2024 IECC Residential Existing Buildings Radon