The International Building Code (IBC) either is in use or adopted in all 50 states of the United States of America, as well as the District of Columbia, Guam, Northern Marianas Islands, the U.S. Virgin Islands, and Puerto Rico. However, as it is the International Building Code, and part of a series of International Codes (“I-Codes”), it is used in multiple locations worldwide, including the 15 countries of the Caribbean Community and Common Market (CARICOM), Jamaica, and Georgia. Furthermore, the IBC has served as the basis for legislative building codes in Mexico, Abu Dhabi, and Haiti, among other places.
IBC Development
The International Code Council (ICC) promulgates a new International Building Code every 3 years through the ICC Code Development Process. As such, the current version of the IBC is the 2024 edition, also known as ICC IBC-2024.
Developed through the review of proposed changes submitted by code enforcement officials, industry representatives, design professionals, and other interested parties, the 2024 International Building Code, just as its mass of predecessors, establishes minimum guidelines for building systems that make possible the use of new materials and new building designs. This is carried out in a manner that provides a reasonable level of safety, public health, and general welfare through prescriptive and performance related guidelines.
International Building Code: What’s Covered
In general, the IBC is focused on means of egress facilities, stability, sanitation, adequate light and ventilation, energy conservation, and safety to life and property from fire, explosion, and other hazards. These topics are addressed throughout the 35 chapters of the expansive ICC IBC-2024 document, which each cover a separate topic like Types of Construction (Chapter 6) and Steel (Chapter 22), and Appendices A-P.
While the International Building Code (ICC IBC-2024) serves as the basis for laws and regulations in communities across the United States and in other countries, it is used in a variety of nonregulatory settings, including voluntary compliance programs, the insurance industry, certification of individuals and buildings, U.S. federal agencies, facilities management, best practices benchmarks, and reference works.
International Building Code: Changes to the 2024 Edition
ICC IBC-2024 is a hefty document, containing a plenitude of sections that together comprise over 750 pages. It has undergone numerous changes from the 2021 edition, including:
- Section 104, “Duties and Powers of the Building Official,” was reformatted, and the approach for reviewing for code compliance was significantly updated to reflect the current manner that alternate materials, designs and methods are evaluated.
- Provisions for tornado loadings were added.
- Wind, earthquake, and snow loads were updated.
- The updated design rain loads are now based on the summation of the static head, the hydraulic head, and the ponding head.
- Updates were made to risk categories including photovoltaic (PV) panel systems and facilities providing power generation.
- Provisions for temporary structures were updated and expanded.
- New provisions were added for the wind resistance of aggregate-surfaced roofs.
- Provisions were updated for roof coverings underlayment.
- New special inspection provisions were added for metal building systems.
- New provisions were added for structural concrete reinforced with glass-fiber reinforcement.
- Chapter 19, “Concrete,” was updated and reformatted.
- There was an increase in the allowable height of a group R-2 occupancy building with a NFPA 13R sprinkler system.
- Occupiable space requirements now apply if a roof is usable for anything more than maintenance or repair and occupants must have access to multiple egress options from a story based on the occupant load and the story requirements.
- Adult changing tables are now regulated where they are provided and are also required in large assembly and mercantile, college lecture hall/classroom buildings, and highway rest stops.
- Updates were made on how supporting construction for exterior walls is to be fire-resistance-rated, especially in the case of a parapet.
- Additional exceptions were provided for shaft enclosures, including new allowances for openings and penetrations.
- Carbon monoxide (CO) detection is now required in all occupancies where a CO-producing device is present.
- Several updates were made to the vapor retarder provisions for consistency with the IRC and IECC. The changes also provide additional options and better guidance for allowable types and locations of permitted vapor retarders.
- Clarification was provided as to when testing in accordance with NFPA 285, related to vertical and lateral flame propagation, is required.
- New Appendix P, “Sleeping Lofts,” was added.
In addition, there were several changes meant to improve readability and usability, such as moving to a single column text format. Also, while code changes were previously marked by the code edition year in the margins, updates are now noted by QR codes.
International Building Code: Changes to the 2021 Edition
The previous edition of the IBC was also a significant revision. ICC IBC-2021 went through numerous changes from the 2018 edition, including but not limited to:
- Puzzle rooms (escape rooms) were defined and regulated as amusement areas (now requiring compliance with Section 411, “Special Amusement Areas”).
- For educational occupancies (Group E), enhanced classroom acoustics in compliance with ICC A117.1 are to be provided in all classrooms with a volume of 20,000 cubic feet or less.
- The use of intermodal shipping containers was specifically addressed.
- Automatic sprinkler protection became required in Group S-2 open parking garages where any fire area exceeds 48,000 square feet.
- ICC A117.1-2017 was adopted (you can learn more about this standard in our post ANSI A117.1-2017: Accessible and Usable Buildings).
- The 2021 IBC snow map was updated to match ASCE 7 snow maps, and secondary rain loads were updated to be consistent with ASCE 7 (you can learn more about this standard in our post ASCE/SEI 7-2022: Minimum Design Loads and Associated Criteria for Buildings and Other Structures).
- Frost protection for egress doors was added to the foundation requirements.
- Three new types of construction (Types IV-A, IV-B, and IV-C) allow mass timber buildings of taller heights, more stories above grade, and greater allowable areas compared to existing provisions for heavy timber buildings.
Any user of International Building Code who wants to see further technical changes made to the 2021 IBC can find them noted through solid vertical lines in the document’s margins.
International Building Code: Changes to the 2018 Edition
For any users who need to know about the updates made even further back in the history of the code, some highlights of the changes made to ICC IBC-2018 from the 2015 edition include:
- Accessory storage spaces of any size became permitted to be classified as part of the occupancy to which they are accessory.
- New code sections were introduced to address medical gas systems and higher education laboratories.
- Use of fire walls to create separate buildings was limited to only the determination of permissible types of construction based on allowable building area and height.
- Where an elevator hoistway door opens into a fire-resistance-rated corridor, the opening should be protected in a manner to address smoke intrusion into the hoistway.
- The occupant load factor for business uses was revised to one occupant per 150 square feet.
- The minimum lateral load that fire walls are required to resist became five pounds per square foot.
- Wind speed maps were updated, including maps for the state of Hawaii.
Other I-Codes by the International Code Council
ICC IBC-2021 does not apply to the repair, alteration, change of occupancy, addition, and relocation of existing buildings, as this is instead the focus of ICC IEBC-2024: 2024 International Existing Building Code. In fact, there are numerous “I-Codes” published by the International Code Council, all of which are fully compatible with one another. These include:
ICC IECC-2021: 2021 International Energy Conservation Code (Learn more in our post 2021 International Energy Conservation Code)
ICC IFC-2024: 2024 International Fire Code (Learn more in our posts 2021 International Fire Code and Commentary to the International Fire Code)
ICC IFGC-2024: 2024 International Fuel Gas Code
ICC IMC-2024: 2024 International Mechanical Code
ICC IPC-2024: 2024 International Plumbing Code
ICC IPMC-2024: 2024 International Property Maintenance Code
ICC IPSDC-2024: 2024 International Private Sewage Disposal Code
ICC IRC-2021: 2021 International Residential Code
ICC ISPSC-2024: 2024 International Swimming Pool And Spa Code (ISPSC)
ICC IWUIC-2024: 2024 International Wildland-Urban Interface Code
ICC IZC-2024: 2024 International Zoning Code
ICC PC-2024: 2024 ICC Performance Code for Buildings and Facilities
ICC IBC-2024: 2024 International Building Code and other ICC standards are available on the ANSI Webstore. Those who need several I-Codes might be interested in the ICC International Building Code Package (IBC).