IAPMO Publishes 2021 Editions of Uniform Plumbing Code, Uniform Mechanical Code

The International Association of Plumbing and Mechanical Officials has published the 2021 editions of the Uniform Plumbing Code and Uniform Mechanical Code in both hard-copy and electronic versions, completing a three-year consensus development cycle accredited by the American National Standards Institute.

Significant changes to the UPC include:

  • New Appendix N – Impact of Water Temperature on the Potential for Scalding and Legionella Growth
  • New provisions for backflow prevention devices, assemblies and methods
  • New provision for temperature-limiting devices
  • New guards and rails requirements for installation of equipment and appliances on roofs
  • New requirements for the discharge of temperature- and pressure-relief valve piping
  • New provision on leak detection devices
  • New provisions for potable water pumps
  • New standards for drain, waste and vent pipe and fittings
  • New provisions for drain waste and vent cleanouts
  • Circuit vent provisions have been updated and expanded
  • Updated fuel gas provisions
  • Updated medical gas provisions, including reordering of categories for ease of use

Significant changes to the UMC include:

  • New Appendix F – Geothermal Energy Systems
  • New guards and rails requirements for installation of equipment and appliances on roofs
  • New ventilation requirements for transient and nontransient occupancies
  • New ventilation requirements for indoor air quality for residential occupancies
  • Revisions to the requirements for air ducts, including factory-made air ducts and dampers
  • New provisions for factory-built grease ducts
  • New provisions for refrigeration systems, including pressure-limiting devices and hydrostatic expansion
  • Revisions to the sizing requirements for natural gas and propane piping systems
  • Modifications to the pressure-rating requirements for hydronic piping applications
  • New requirements for fuel gas piping appliance shutoff valves, test pressure and overpressure protection devices
  • New tube fastener provisions for radiant heating and cooling
  • New requirements for residential compressed natural gas fueling systems
  • New fire-extinguishing equipment and carbon monoxide detection requirements for exhaust systems

The 2021 Uniform Codes is available electronically, accessible from a computer or mobile device.

The public at large is encouraged and invited to participate in IAPMO’s open consensus code development process. A code development timeline and other relevant information are available at IAPMO’s website: https://www.iapmo.org/codes-standards-development/code-development.

The 2021 UPC and 2021 UMC may be purchased through the IAPMO bookstore at: https://bit.ly/2JnKtaf.

For questions regarding the UPC, contact Enrique Gonzalez at 909-230-5535 or email enrique.gonzalez@iapmo.org. For the UMC, contact Zalmie Hussein at 909-218-8122 or email zalmie.hussein@iapmo.org.