An Overview of ACI 318-25 for the 2027 IBC
The latest edition of ACI 318 Building Code Requirements for Structural Concrete was released at the end of January, 2025, although a printed version did not become available until late July. It is expected to be adopted by the 2027 IBC.
ACI 318-25 introduces significant updates, including a new sustainability appendix and a new appendix on performance-based wind design, revised requirements for post-installed reinforcing bars, and enhanced provisions for shear friction. Additional updates include improvements to deep foundation requirements across all seismic design categories and clarified guidelines for cantilever and basement wall shear design.
The document also features numerous advancements in seismic design provisions (including significant relief from the severe shear design requirements for special shear walls in ACI 318-19), and modifications to development length equations. Enhanced language on the development, embedment, and anchorage of reinforcement, as well as new strength reduction factors for breakout failure, are also included, along with updated guidance for developing closely spaced bars in tension.
About S.K. Ghosh
S. K. Ghosh Ph.D., is a highly acclaimed speaker and author on seismic-related issues and concrete design, and has been involved with the development of national codes and standards.
About Kirsten Zeydel, SE
Kirsten Zeydel, SE, is the Director of Design at Nevell Group, Inc. and a Structural Consultant with S.K. Ghosh Associates. She is a licensed Structural Engineer based in Southern California, with over twenty years of experience in structural design. Kirsten has experience with all structural materials.