The United Association of Journeymen and Apprentices of the Plumbing and Pipefitting Industry and the Natural Resources Defense Council have proposed a code change to the 2015 edition of IAPMO’s Uniform Plumbing Code to require insulation of all hot water piping systems such as those serving lavatories, showers, dishwashers and kitchen sinks.

To curtail water waste in new buildings, NRDC and the UA proposed that the 2015 edition of IAPMO’s Uniform Plumbing Code require insulation of all hot water piping systems such as those serving lavatories, showers, dishwashers and kitchen sinks. The Uniform Plumbing Code is the model for local and state plumbing codes now in force in at least 19 states.

 The following is a statement from William P. Hite, general president of the United Association:

“As IAPMO drafts its next set of codes, we recommend insulating hot water piping to reduce the waste of energy and water in hot water systems.  This proposal is indicative of the UA's commitment in construction, service and maintenance practices required for energy efficient green buildings.  Throughout the construction industry, there are untapped opportunities to make our buildings and our economy more efficient, and we should seize these opportunities to create good jobs for American workers.”

Peter Lehner, executive director at the Natural Resources Defense Council, issued the following statement:

“This proposal is a commonsense solution to an everyday problem that we can all warm up to. Most of us waste too much time, energy and money waiting for hot water to come out of our faucets and showers. By combining efficient designs, proven energy-saving materials, and skilled labor, we can build smarter buildings that curb this waste and improve the amenity of new buildings. This proposal will not only save homeowners and renters money on their monthly utility bills but also protects our environment by cutting energy and water use.”

In a typical three-bedroom, two-bath home, an estimated 12% of all hot-water use is wasted, according to a 2009 analysis led by Robert Hendron of the National Renewable Energy Laboratory. Purging at showers, kitchen sinks and lavatory faucets was responsible for 95% of the estimated total of nearly 3,000 gal. of hot water waste annually. 

The NRDC estimates pipe insulation can reduce this waste of water and energy by 15% to 30%. Of course, many new homes are built with more hot water outlets than the NREL model’s base case and with hot water distribution systems that are far less efficient.

 For example, some new homes are built with their water heaters located in the garage, far away from showers and faucets. The proposed revision to Uniform Plumbing Code will ensure that hot water pipes supplying these fixtures are fully insulated.