About Plumbing Codes

What are plumbing codes?

Plumbing codes, like all building codes, are rules that provide for safe and civilized living. Building officials want their codes to make a positive difference in their constituents’ lives.

Plumbing codes should have real-world implications, rooted in scientific data. Codes aren’t just the fine print. Plumbing systems protect us against waterborne disease, lead poisoning, scalding, hair entrapment and drowning, disembowelment, flooding, electrocution, asphyxiation and combustion.

Plumbing systems keep us safe and strong Uniform Plumbing Codes keep plumbing systems safe.

After public health and safety considerations have been assured, plumbing codes need to set the right balance between short-term building costs and long-term operating and maintenance costs.

Plumbing codes help communities turn intention into actionable, realistic regulations that   avoid undue regulatory burdens while mitigating unintended consequences.

What is the Uniform Plumbing Code?

Provisions of the Uniform Plumbing Code® (UPC) protect more than half of the world’s population. The International Association of Plumbing and Mechanical Officials (IAPMO) publishes the UPC model code.

The UPC model plumbing code is enforceable rather than interpretative, with built-in flexibility to embrace emerging water technologies.

How is the Uniform Plumbing Code changed?

The UPC is a consensus-based document developed by subject matter experts representing the broad range of the industry. Changes must be approved by a super-majority: a two-thirds affirmative vote of our diverse stakeholders, including plumbers, engineers, manufacturers, environmentalists and code officials – all people very knowledgeable about plumbing.

A standards-based consensus process helps avoid a situation where the code can be changed at the last minute by any one single constituency.

This is why the UPC is designated as an American National Standard by the American National Standards Institute.

How often is the Uniform Plumbing Code updated?

The UPC is revised every three years under IAPMO’s ANSI-accredited development process.

What is the International Plumbing Code?

The International Code Council (ICC) publishes the International Plumbing Code® (IPC) model code.

The IPC frequently cites construction cost savings as a benefit of their model code, but neglects to address total lifecycle costs. For example, the IPC allows for the use of air admittance valves (AAV)  as an alternative to roof venting. That practice may save on upfront construction costs but at the risk of future costs to home and building owners down the road if/when the mechanical AAV fails. At worst, an AAV failure can enable toxic sewer gases to impact building occupants. Read more about plumbing and public health.

How is the International Plumbing Code changed?

Changes to the IPC may be proposed by interested parties; however, only code officials are allowed to vote at the code cycle’s final development code hearings.

Plumbing systems experts are excluded from this final vote.

A simple majority vote by a single stakeholder group creates a monopoly that can result in a last-minute change to the IPC.

How often is the International Plumbing Code updated?

The IPC is updated every three years.

IPC vs UPC Plumbing Codes: What is the difference?

The UPC is a far more comprehensive plumbing code than the IPC. Examples of technical content covered by the UPC and not the IPC include:

  • Appliance Venting and Combustion Air Provisions (Chapter 5)
  • Fuel Gas (Chapter 12)
  • Calculating Peak Water Demand (Appendix M)
  • New provisions addressing Legionella in plumbing systems (Appendix N)
  • Potable rainwater catchment systems (Appendix K)
  • Sustainable practices (Appendix L)
  • Approved methods to design the water distribution system (Chapter 6)
  • Medical gas (Chapter 13)
  • Manufactured/mobile home parks and recreational vehicle parks (Appendix E)
  • Firefighter breathing air replenishment systems (Appendix F)
  • Private sewage disposal systems (Appendix H)
  • Industry installation guidelines (Appendix I)

An independent study confirmed that the 2018 ICC code changes increased costs on average 7.57% for commercial buildings and 14.20% for homes over 2015 editions.

The organizations behind the codes are also significantly different. IAPMO has nearly 100 years of experience in plumbing systems. Conducting original research to help building officials make sense of today’s sophisticated water-related technologies, IAPMO builds a bridge between generalist building inspectors and the increasingly sophisticated water-related technologies in today’s built environment.