To view the figures and tables associated with this article, please refer to the flipbook above.
Champlain Tower South, which collapsed in June of 2021, was a 12-story residential concrete tower, originally constructed in 1981 and located in the Town of Surfside in Miami-Dade County Florida. The collapse resulted in 98 deaths, one of the worst in U.S. history. The public investigation into the causes of the collapse has been led by a team at the National Institute of Science and Technology (NIST). Although the final NIST report is not expected until later in 2026, NIST has shared preliminary findings. Today, more than 5 years after the collapse, we are beginning to see how the lessons learned from that collapse may impact national building codes, which are often updated on 3-to-6-year cycles.
Building codes are adopted and enforced by individual jurisdictions throughout the country. Although jurisdictions are free to write their own building code, most jurisdictions adopt national model codes, with revisions as necessary. The simplest (and most common) model is for a local jurisdiction to adopt the International Code Council (ICC) codes. The main ICC structural code for existing buildings is the International Existing Building Code (IEBC). The ICC codes also reference standards developed by other important national standards developers, such as:
- American Society of Civil Engineers (ASCE).
- American Concrete Institute (ACI).
- American Institute of Steel Construction (AISC).
- The Masonry Society (TMS).
Florida Codes and Laws
Florida is one of the few states that has a state-wide building code. Florida’s legislature created the Florida Building Code (FBC) in 2002, which is a modified version of the IBC. The IBC (and the FBC) are updated every 3 years. Some of the material standards, like the steel and concrete standards, are only updated every 5-6 years.
Although it can take years for national codes and standards to be updated and adopted, Florida quickly passed laws requiring inspections of older condo buildings. Florida State Bill 4D (SB4D) was passed in May 2022, as well as Senate Bill 154 (SB154 June 2023) and Florida House Bill 913 (HB913 - June 2025). Together, these bills require milestone structural inspections and reserve studies for condos that are three stories and higher. Structural inspections are required for buildings 30 years or older (or 25 years old if within 3 miles of the coastline). Prior to the Champlain Tower South collapse (since 1975), milestone structural inspections were required for buildings 40 years and older. Additional inspections are required every 10 years. The reserve studies are meant to ensure that condo associations are adequately funded to perform required maintenance and repairs. Many other cities and counties in the country have their own local ordinances requiring structural and facade inspections of existing buildings at regular intervals.
National Standards
ASCE is responsible for some important standards and guidelines, including ASCE/SEI-11, Guideline for Structural Condition Assessment of Existing Buildings. Although this is a common document relied upon for structural condition assessments, it was last updated in 1999. After the Surfside condo collapse, the committee responsible for this guide was reformed and tasked with publishing an updated standard. The Call for New Members was announced in July of 2023. That committee is now active, and development of a new standard is underway with hopes for publication by 2028.
The Champlain Tower South collapse spurred much public discussion regarding the fact that a structural building assessment had been performed there in 2018. That 2018 Structural Field Survey Report noted deterioration, cracking, spalling, and other issues throughout the property that required structural repair. However, the condo’s association did not immediately perform the recommended repairs, partially due to lack of funding and possibly due to a lack of perceived urgency. The newly formed ASCE/SEI-11 committee will be expected to provide guidance on how best to communicate the appropriate degree of urgency for any recommended repairs.
Similarly, ICC appointed a new committee in September 2024 to develop a new document: ICC-1500 Standard for Existing Building Safety Inspections. According to the first public review draft, the goals for ICC-1500 include establishing reporting standards and assessment intervals for existing buildings. ICC-1500 is expected to define annual maintenance inspections for owners and require the involvement of licensed professionals to address any discovered issues. ICC-1500 may establish a requirement for visual building assessments by licensed professionals every 10-15 years. The committee is targeting publication in time for reference into the 2027 IBC.
Since Champlain Tower South was a concrete building, NIST gave a thorough review of the concrete design and construction details of the building. Much of the NIST investigation has focused on the column-slab details of the building. While NIST has reported on several specific issues, such as concrete cover over slab reinforcing bars, column reinforcement congestion, and lack of column ties, none of those issues represent a deficiency in the current Building Code for Structural Concrete (ACI-318-25). Champlain Tower South was designed according to the 1977 ACI-318 edition. Since then, the ACI-318 provisions for punching shear have changed and detailing requirements for structural integrity have been added. Additionally, current ACI-318 provisions have many more provisions regarding chloride exposure. At this time, it does not appear that any ACI-318 provisions will be revised due to the findings from the collapse investigation.
However, the Surfside collapse may bring more attention to ACI-562 Assessment, Repair, and Rehabilitation of Existing Concrete Structures. Traditionally, the IEBC was used by engineers for evaluations of damage and repairs to existing concrete buildings. First published in 2013, ACI-562 is a performance-based code meant to standardize the assessment and repair practices specific to the concrete industry. ACI-562 was not referenced in the IEBC until the most recent 2024 edition, in which ACI-562 is included as an approved material specific alternate to general provisions of the IEBC. IEBC-24 Section 405.1.1 states that “Repair of structural concrete shall be permitted to comply with ACI 562 Section 1.7,” with some exceptions. Licensed professionals working in a jurisdiction that adopts the 2024 IEBC now have a simple code path to use the methods outlined in ACI-562 for the assessment and repair of existing concrete structures for their projects. The current version of ACI-562 (2025) requires that the engineer determine whether severe strength deficiencies and dangerous conditions are present during an assessment; however, it does not include requirements or guidance for the engineer related to notifying the owner or jurisdiction of the timing and cost associated with the required repairs or strengthening.
Although Champlain Tower South was a concrete building, the steel building code writers also recognized a need to improve the code provisions for existing steel buildings. Appendix 5 of AISC-360 Specification for Structural Steel Buildings provides requirements for the “Evaluation of Steel Structures.” In the 2022 edition of AISC-360, Appendix 5 was only four pages long, addressing topics like material properties and load testing. The next edition of AISC-360 will be issued in 2027. According to the public review draft of AISC-360-27 from August 2025, one of the major changes will be expansion of the scope of Appendix 5. In the new draft, Appendix 5 is titled “Existing Structures” and “applies to the evaluation, alteration, addition, and repair of existing steel structures.” The draft provisions of Appendix 5 appear to have more than tripled in length. Appendices are required provisions of the AISC-360 specifications. In jurisdictions where AISC-360-27 is adopted, engineers will be required to comply with the expanded Appendix 5 provisions. Similar to ACI-562, the intent of the expanded material-specific repair provisions in the steel building code is to improve the performance of existing buildings and extend useful service lives. The expanded scope of Appendix 5 is not yet final. Watch for AISC-360-27 to see which new provisions are aproved.
Similarly, TMS has a committee tasked with developing a document with guidance for repair of existing masonry structures, TMS 405. The first public review period is planned for summer 2028, with hopes of publication in fall 2029, and reference by the ICC codes in 2030.
Conclusion
The final NIST report presenting their analysis of the Champlain Tower South collapse is scheduled for release later this year (2026). While that report will certainly add to overall lessons learned from this collapse, much has already been shared during periodic updates. Code and standards writers have spent the last four years considering the lessons from the condo’s collapse and how to improve building codes to help make structures safer. Most codes and standards writing committees follow a “consensus based” process, meaning new provisions should be based on the experience of industry professionals on the committee, as well as their review of current research and findings. As the current code cycle concludes, and new documents are published, engineers will have plenty of time to digest the new recommendations and requirements related to existing buildings. Even once the 2027 IEBC is published, jurisdictions often take years to adopt a new building code. Meanwhile, the various publications inevitably will have gaps and coordination issues that will need to be addressed in the future. ■
Disclaimer
This article presents the opinions of the authors, who have general understandings of the development of some relevant codes and standards. However, until those documents are published in their final form, the actual provisions and recommendations are unknown. Furthermore, there may be other relevant building codes enacting revisions related to the CTS collapse that were not discussed in this article.
About the Authors
Jim Foreman, PE, SE is an Associate at Martin/Martin and an AISC committee member, specializing in investigative engineering. He leads a team of engineers that provide expert witness services for construction defect attorneys.
Benjamin Estrich, PE, SE, is an Associate at Martin/Martin and an ACI committee member. He leads a team of engineers and architects who help owners assess, repair, and maintain their existing concrete structures.
Nicole Lane, PE, SE, is a Principal at Martin/Martin and an ASCE/SEI-11 committee member. She leads a team of engineers focused on the repair and renovation of existing buildings.
References
IEBC:
