Integrating Water Systems

The following excerpt is from IREM’s publication, A Practical Guide to Green Real Estate Management (IREM © 2009): 

Integrating Water Systems Water reuse systems cross the boundaries among kitchen and bath, HVAC, and landscaping water needs. Graywater systems take water from certain uses (usually anything but toilet waste can be classified as graywater) and reuse it for flushing toilets, cooling systems, landscaping, and other areas where potable water isn’t necessary. Rainwater catchment systems perform similar functions, but use collected rainwater instead. 

Integrating these water reuse systems into your existing buildings can be a challenge and may involve reworking your current plumbing system or adding new equipment, but once installed, they’ll offer significant water savings. To learn more about rainwater catchment, visit the American Rainwater Catchment Systems Association Web site. Optimizing your water heating system is another cross-cutting way to save water. The less time it takes your water heaters to get water to acceptable temperatures, the less time users will need to leave the water running while they wait. Performing regular maintenance on water heating systems can save both energy and water. 

Submetering is another strategy that applies to all water-consuming activities in your portfolio. Keep track of your water intake for specific uses by devoting unique submeters to outside water use, cooling systems and specific areas of each building—such as individual tenant spaces. The more places you submeter water consumption, the quicker you’ll be able to identify the source when usage surges. Also, make this information accessible to tenants and residents, if their spaces or units are submetered. Heightened awareness of how much water they use is the most effective way to encourage occupants to use less. For example, submetered multifamily units have been known to use 15 percent less water than units where water use is included in rent, according to the National Multi Housing Council. 

Trade-Offs 

There are many examples of trade-offs among different environmental components—particularly energy and water efficiency. It’s important to carefully evaluate these trade-offs for any investment or upgrade you make. Whether you favor one benefit or another depends on your specific circumstances. For example, in hot, dry climates with frequent water shortages, water efficiency may win out over energy; the opposite may be true in areas with exceptionally high electric rates. On the flip side, certain measures can have synergistic energy and water savings, as illustrated by many of the examples listed above. Find the energy- and water-saving measures that will have the greatest impact for your portfolio, and take a comprehensive approach for the greatest results.