Code Corner: 2021 International Plumbing Code Chapter 6: Water Supply and Distribution

The International Codes® (I-Codes), developed by the International Code Council, are a family of fifteen coordinated, modern building safety codes that help ensure the design and construction of safe, sustainable and affordable structures. 

The I-Codes are the most widely adopted set of model codes globally, implemented in all 50 U.S. states and many countries around the world. 

The Building Safety Journal’s new series, Code Corner, will explore sections of the I-Codes each month, focusing on key elements of these essential codes. This month, we’re spotlighting Chapter 6 of the 2021 International Plumbing Code® (IPC): Water Supply and Distribution.

607.5 Insulation of Piping

Chapter 6 of the IPC focuses on water supply and distribution. For buildings other than Group R2, R3, and R4 occupancies that are three stories or less in height above grade plane, piping to the inlet of a water heater and piping conveying water heated by a water heater shall be insulated in accordance with Section C404.4 of the International Energy Conservation Code® (IECC). 

For Group R2, R3 and R4 occupancies that are three stories or less in height above grade plane, piping to the inlet of a water heater and piping conveying water heated by a water heater shall be insulated in accordance with Section R403.5.3 of the IECC.

The IECC has requirements for insulation of heated water piping because without insulation, these systems can waste a significant amount of energy and add to the cooling loads of buildings. This code section is somewhat complicated by the fact that the IECC is split into a commercial buildings part (IECC-CE) and a residential buildings part (IECC-RE). 

This code covers residential buildings that the IBC classifies as Group R2, R3 or R4; however, where those buildings are “low-rise” buildings (i.e., three stories or less in height above grade plane), the IECC–RE requirements apply. For all other buildings covered by the IPC, the IECC-CE requirements apply.

This section is controlled by the IECC, as indicated by the [E] at the beginning of the section number.

Why is a section on insulating heated water piping in the IPC? On most large projects, insulation installation is performed by an insulation contractor and those large projects often have insulation details on the drawings so that the plumbing designers/installers understand what allowances to make around the piping to accommodate the insulation thicknesses. But not all projects are large nor have such insulation details on the drawings. The plumbing designer and installer need to understand what the IECC’s minimum insulation requirements are so allowances can be made for the insulation in accordance with the code (the IECC). 

For more on the insulation of piping, and to learn more about the IPC, click here. To stay updated on the latest PMG industry news, subscribe to the Code Council’s PMG newsletter here.