Three Ways the NAHB Residential Construction Performance Guidelines Could Be Better

The sixth and newest edition of the NAHB Residential Construction Performance Guidelines delivers value to builders, homeowners, and the entire residential construction industry. Since the document is all about performance, may I suggest three additions from the plumbing sector that will deliver greater value and better performance over the life of the home:


1) Require the most up-to-date peak flow rate calculations to specify new residential plumbing systems

As has been widely reported, peak water demand has changed since the advent of high-efficiency fixtures and appliances. We know builders who use the most up-to-date peak flow rate calculations in new single-family homes can save up to $4,500 in water and sewer connections. Their clients can save up to $250 a year in ongoing water and sewer charges. The savings increase exponentially for builders of multi-family structures, up to $250,000 for a 200-unit high-rise.

The construction savings is just the beginning, as oversized pipes can compromise building performance. Large-volume pipe diameters cause hot water delivery delays to low-flow fixtures, wasting water and energy. Additionally, oversized pipes can create water quality issues.

The updated water demand calculations are widely available as the IAPMO Water Demand Calculator,  a free app or spreadsheet download.


2) Require Leak Detection Devices

To save water and prevent mold, leak detection devices are as necessary as smoke and carbon monoxide detectors to prevent a small problem from growing into a big disaster.

The ANSI/CAN/IAPMO Z1349-2021 standard is a good guide to the essential performance features of these devices, which should include:

  • Automatic shut‐off or electronic alarm notifications when a leak is detected or the equipment malfunctions (e.g., automatic water leak detection and control device).
  • Detection of water that is external to the piping system, which may indicate a leak.
  • Establishing standard water flow patterns to monitor for anomalies.
  • Monitoring hydraulic conditions — water pressure, temperature, and flow — within the main or branch circuit.
  • Monitoring local weather conditions for freeze potential.
  • Ongoing analysis of sensor readings and system conditions to ensure system integrity.
  • Pressure-based or other means of micro leak testing for detection of pinhole leaks or dripping fixtures.
  • Providing hardwired or remote access to control a valve (e.g., remotely controlled valves).


3) Require High Efficient Reverse Osmosis Water Systems

Residential point-of-use reverse osmosis (RO) water treatment systems can help reduce drinking water contaminants. As droughts and natural disasters compromise drinking water quality, ROs can keep homeowners’ drinking water safe while reducing the burden on community systems.

RO systems work by forcing water under pressure through a membrane, removing many contaminants. But many ROs also waste a lot of water.  For example, typical RO systems can discharge four gallons of wastewater for every gallon of drinkable water.

The ASSE 1086 standard governs not only material safety, structural integrity, and contaminant reduction claims; it requires a minimum efficiency requirement of 40%, only discharging 1.5 gallons of wastewater for every gallon of drinking water. These efficiency requirements make this standard unique in addressing the dual heads of performance: safety and sustainability.

Keeping builders and their clients in the know about advancements that reduce housing costs and save water while keeping homes and families safe is an essential mission for all of us in the plumbing industry. Consider these three recommendations for new homes that live up to that promise.


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