W04: Water-Efficient Urinals

Requirement Summary

This measure can be claimed when urinals in all bathrooms of the building have a flush volume which is lower than the base case. The actual flush rate of urinals must be entered in the software in all cases, irrespective of the value.

Intention

Fitting low-flush urinals reduces the water used for flushing, ensuring efficient water use and a high level of user satisfaction with flushing performance.

Approach/Methodologies

The flush volume is measured in liters/flush. The default flush volumes for the improved case must be replaced with the actual values provided by the manufacturer. The maximum flush volume of the urinal fixture as per the manufacturer must be specified.

If the flow rates of the urinals vary across a project, a weighted average must be used. Multiple measurements must be made across a variety of locations and floors to come up with a weighted average.

There are urinals available that do not use any water, referred to as waterless urinals. For waterless urinals, a value of 0.001 Lt/flush must be entered in the field provided.

Potential Technologies/Strategies

Urinals are only provided in bathrooms for males and only accept liquid waste. Their water saving potential depends on the number of male users in the building.

Urinals that are designed to be non-adjustable above their flush volume and that are provided with drain trap functionality tend to save more water. Pressurized flushing devices and a valve provide controls and therefore water savings.

In some cases, water efficient urinals can result in an increased risk of blockages caused by the reduced volume of water. The Environmental Protection Agency in the U.S. has a label, “WaterSense,” with tests for water efficiency and performance. The WaterSense label helps purchasers easily identify high–performing, water– efficient urinals, which can be found on the EPA website.

Relationship to Other Measures

This measure is not affected by any other measure. However, this measure impacts building energy consumption due to a change in the energy use of water pumps as the total volume of water pumped changes (this portion of the energy consumption is included within the Energy Use category “Other”).

Assumptions

The base case assumptions vary by location. Globally, the typical baseline is a flush volume of 4 liters; the improved case assumes a flush volume of 2 liters. EDGE assumes on average that urinals are used two out of three instances of bathroom use in the male restrooms.

Compliance Guidance

Design Stage	Post-Construction Stage
At the design stage, the following must be used to demonstrate compliance:  Plumbing drawings/specifications including make, model and flush volume of the urinal(s); or  Manufacturer’s data sheet for urinal(s) with information on the flush volume.	At the post-construction stage, the following must be used to demonstrate compliance:  Photographs of installed urinal(s); or  Purchase receipts and delivery note for urinal(s).

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