The 2024 International Codes® (I-Codes®) have undergone
substantial formatting changes as part of the digital transformation strategy
of the International Code Council® (ICC®) to improve the user experience. The
changes, promoting a cleaner, more modern look and enhancing readability and
sustainability, include:

• Single
      column text format and modernized font styles improves readability
  


• QR
      Codes replace vertical margin sidebars and arrows to identify code changes
      more accurately
  


• Shading
      for table headers and notes improves locating tables and applicable notes
  


• Grouping
      of associated content brings tables and figures immediately after the
      parent section
  


• Users
      have capability to validate authenticity of their book and register it
      with the ICC to receive incentives.
  

The International Mechanical Code (IMC®) establishes minimum
regulations for mechanical systems using prescriptive and performance-related
provisions. The IMC® was developed with broad-based principles that make
possible the use of new and innovative materials, methods and design. For the
most current adoptions details go to
International Code Adoptions.

Important changes in the 2024 IMC include:

• Provisions
      prohibiting the use of domestic ductless range hoods in Groups I-1 and I-2
      were removed.
  


• An
      identification requirement was added for Group A2L and B2L refrigerants.
  


• The requirements
      for machinery rooms containing Group A2L refrigerants were changed and
      Group B2L refrigerants were added to the provisions.
  


• Limits
      for the use of Group A1 and A2L refrigerants changed in high probability
      systems used for human comfort, unless permitted as excepted.
  


• UL
      2158A Standard was added to the requirements for commercial dryer exhaust.
  


• Ventilation
      requirements for outpatient healthcare facilities to match the
      requirements in ASHRAE 62.1-2019.
  


• Addition
      of a new minimum landing at the roof hatch for personnel to safely use the
      hatch when accessing the roof for repair and maintenance.
  


• Addition
      of a new testing option for grease ductwork.
  


• Requirements
      for steam baths were added.
  


• A new
      standard requirement for refrigeration systems containing carbon dioxide
      was added.