Unveiling the 2024 Editions of the International Plumbing Code and the International Mechanical Code

The launch of the 2024 International Codes® (I-Codes) has begun, starting with the International Plumbing Code® (IPC) and the International Mechanical Code® (IMC).

The I-Codes, developed by the International Code Council, are a family of fifteen coordinated, modern building safety codes that help ensure the engineering of safe, sustainable, affordable and resilient structures. The I-Codes are developed through a transparent and democratic process that allows anyone to get involved and helps ensure we have the best possible model safety codes to support the built environment.

SEE RELATED: Building Codes and Standards: Bringing Science to Building Safety

The 2024 IPC and IMC are the first of the 2024 I-Codes to undergo substantial formatting changes to improve the user experience and better align print and PDF versions of the I-Codes with the Code Council’s Digital Codes® content.

This is the biggest change in the format of the I-Codes in 25 years.

SEE RELATED: An Introduction to the Updated 2024 International Codes

2024 International Plumbing Code

The 2024 IPC provides minimum regulations for plumbing facilities and includes plumbing fixture provisions, along with accessibility requirements from the ICC A117.1 Accessibility Standard, making the IPC the most comprehensive plumbing code around.

Important changes from the 2021 IPC to the 2024 IPC include:

• Provisions added for support of buried piping beneath buildings where expansive soil conditions exist. 
• Requirement added for tracer wire for buried plastic sewer piping.  
• Option added for vacuum testing of drain-waste-vent (DWV) piping. 
• Plumbing fixture requirements significantly updated for various Group I occupancies. 
• Exception added for allowing special locking mechanism for doors to multiple-user toilet facilities. 
• Plastic pans for gas-fired water heaters required to be tested in accordance with ASTM E84 or UL 723. 
• Showerhead flow limited to 2.0 gallons per minute with performance complying with high efficiency requirements. 
• Installation standards added for solvent-cemented plastic piping joints. 
• Standards added for chemical waste piping materials.

2024 International Mechanical Code

The 2024 IMC establishes minimum regulations for mechanical systems using prescriptive and performance-related provisions.

Important changes from the 2021 IMC to the 2024 IMC include:

• Requirements prohibiting the use of domestic ductless range hoods in Groups I-1 and I-2 were removed.   
• Group A2L and B2L refrigerant requirements have been added in line with ASHRAE and UL Standards. [adding refrigerant piping identification requirements, machinery room requirements, and allowing the use of A2L refrigerants high probability systems used for human comfort.]  
• Leak detection monitoring with alarm requirements have been added where the discharge from safety relief valves is not “readily visible” to occupants. 
• Outside air requirements for dwelling units have increased in line with ASHRAE 62.2. 
• Requirements for exhaust system common ducts serving separate dwelling units have been added requiring the common duct or shaft to be maintained at a negative pressure at all times. 

SEE RELATED: The International Code Council’s Plumbing and Mechanical Codes Are Paving the Way for More Resilient Communities 

Where to Find the 2024 Editions of the I-Codes 

The 2024 I-Codes will continue to roll out throughout 2023 and into 2024. They will be available for purchase on the Code Council store and will also be available on the Code Council’s Digital Codes Premium®. 

You can purchase the 2024 IPC and IMC, here.