Standards & Codes for Water Efficiency

Plumbing fittingStandards and codes for plumbing, equipment, appliances, and green building are important in advancing the development of water efficient practices and products and in assuring the longevity of water savings.  The Alliance for Water Efficiency participates in all of the key codes and standards-making organizations to ensure that the most water-efficient and cost-effective practices, products, and technologies are recognized.

What are Standards?

Webster’s defines a standard as: “...something set up as a rule for measuring or as a model to be followed...”  In the world of water-efficient products, standards (or “rules for measuring”) are necessary to establish standard dimensional requirements and the minimum performance level for all manufacturers to meet with their products.  Compliance with established standards, however, is voluntary.  That is, until such time as an American National Standards Institute (ANSI) consensus standard is adopted into law by regulation (e.g., building codes) or legislation (e.g., the National Energy Policy Act – EPAct), the standards have no force of law.

Once adopted, however, new products from new manufacturers entering the U.S. marketplace, or new product models introduced by existing manufacturers, must be measured against the relevant standards and meet specified minimum requirements in order to be sold in the marketplace or installed in buildings. 

Many different U.S. organizations are approved by ANSI as standards-writing bodies, having met certain stringent requirements.  Standards committees and project teams are comprised of a variety of stakeholder interests, and they are required by ANSI to maintain a “balance” of those interests. As such, these groups include representatives of manufacturers, laboratories, government, private sector consultants, and others.  Generally speaking, standards (and their implementing codes) have focused primarily on protecting public health and safety.  In the past 20 years, though, the goal of achieving water use efficiency has been added to the process in many cases.

Learn more about plumbing standards here.

Learn more about green building standards here.

What are Codes?

In addition to standards, plumbing and building codes play an important role in governing the installation and use of water-efficient products.  Codes are promulgated by code authorities and adopted by jurisdictions to protect the health and safety of the citizens. It is important to note that, whereas the national standards approved by ANSI are voluntary consensus-based standards, the codes (which may or may not adopt the national standards by reference) are usually mandatory within the jurisdiction that adopts them.

Like the standards process, the model codes process is complex. There once were five different plumbing code development organizations in the U.S., but mergers have reduced this number to only two key groups.  The International Association of Plumbing and Mechanical Officials (IAPMO) produces the Uniform Plumbing Code (UPC), and the International Code Council (ICC) produces the International Plumbing Code (IPC).  In general, the IPC is more prevalent in the eastern part of the US, and the UPC is more prevalent in the west. Both model codes continuously evolve as a result of constant amendments. Public participation in the amendment process is encouraged by both organizations.  Each of the code-authoring organizations follow a 3-year development cycle to update and publish their respective model codes. When the new updated version of the code is published, IAPMO and ICC encourage all of the jurisdictions to adopt the newest version of the code.

The model plumbing and building codes themselves have no legal status until adopted by jurisdictions such as cities, counties and states.  Where adopted, the codes become as local ordinances and laws.  All jurisdictions can amend the model code before and after adoption, and some do this to better suit local conditions.

For further information on the code process, go here.


The National Energy Policy Act of 1992 (EPAct 92) sets maximum water consumption standards for showerheads, faucets, urinals, and toilets; pre-rinse spray valves (PRSVs) followed in 2005.  Just how those standards are manifested in fixtures (toilets and urinals) and fixture fittings (faucets, showers, and PRSVs) is a function of standard setting and the adoption of those requirements into the plumbing codes as noted above.  Water consumption for various fixtures has become increasingly efficient over the years.  The table linked below this paragraph illustrates the changing water consumption for faucets, showerheads, toilets, urinals, pre-rinse spray valves, clothes washers, and dishwashers from 1980 to 2012.

Water Consumption by Water-Using Plumbing Products and Appliances - 1980 to 2012 


U.S. National Efficiency Standards (fixtures and appliances)

The following link navigates to a PDF document that lists National Efficiency Standards for 14 water-using fixtures and appliances.  The document also lists specifications for WaterSense, Energy Star, and the Consortium for Energy Efficiency, and includes links to related resources.

National Efficiency Standards and Specifications for Residential and Commercial Water-Using Fixtures and Appliances (November, 2016)

U.S. "Green" Specifications for Indoor Fixtures and Appliances

Various "green" standards and guidelines exist for plumbing fixtures and appliances beyond the U.S. National Standards.  These standards and guidelines may be part of voluntary programs such as WaterSense Single-Family New Homes and USGBC LEED for Homes, or codes such as the IAPMO Green Plumbing and Mechanical Code Supplement and the ICC International Green Construction Code.  The linked PDF below contains information on specifications for a variety of standards, codes, and voluntary initiatives.   

Water-Efficient Indoor Products and Systems - U.S. Green Standards, Codes, and Voluntary Initiatives (November, 2016)

Articles, Reports and Other Resources

AWE. (2016). The Status of Legislation, Regulation, Codes & Standards on Indoor Plumbing Water Efficiency
Vickers, A, Bracciano, D. (2014). Low-Volume Plumbing Fixtures Achieve Water Savings. Opflow, 40(7), 8-9.

AWE Webpage: 20 Years of the Energy Policy Act: 18.2 Trillion Gallons Saved 

AWWA. (2001). Impact of the National Plumbing Efficiency Standards on water Infrastructure Investments.