Sector‑by‑sector water intelligence: Multifamily, retail, office

Water scarcity is becoming one of the most material environmental risks for commercial real estate. As drought severity, rising water rates, and regulatory constraints intensify, investors are increasingly expected to demonstrate sector‑specific water management strategies. The GRESB Real Estate Benchmark reinforces this shift, emphasizing water‑stress exposure, operational performance, and evidence‑based reduction pathways. Within the GRESB Real Estate Benchmark, office, retail, and multifamily are consistently the most extensively benchmarked sectors.

Two technologies are foundational to water sustainability reporting across all commercial sectors: smart irrigation controllers and continuous flow monitoring. Weather-based and soil moisture sensor-based irrigation systems reduce outdoor water demand by aligning schedules with actual site conditions. They eliminate overwatering, adjust for rainfall and vegetation needs, and detect mechanical failures such as broken heads or stuck valves. Flow monitoring complements this by providing real‑time consumption visibility, enabling accurate GRESB reporting even when owners lack direct access to water bills. Together, these capabilities form a closed loop: irrigation efficiency drives demand reduction, while flow monitoring verifies savings, detects anomalies, and ensures those gains are not lost to undetected anomalous use. These documented irrigation savings can help demonstrate year-over-year progress in water management and resource efficiency.

Understanding how water use varies across office, retail, and multifamily properties is essential for setting credible targets, prioritizing capital, and demonstrating measurable performance improvements.

Multifamily communities represent one of the most water‑intensive real estate sectors due to continuous domestic demand and high occupancy density. Typical water-use intensity (WUI) averages 45.2 gallons per square foot per year, and over 126 gallons per square foot per year at the high end, according to ENERGY STAR Portfolio Manager water‑use intensity benchmarks.

Senior Housing falls within this category but operates at a measurably higher intensity with a median WUI of 56.4 gallons per square foot per year, roughly 25% higher than general multifamily. Facilities run continuously and depend heavily on water for bathing, laundry, food service, and healthcare support. Many are in water‑stressed Sunbelt markets, and aging infrastructure increases both leak risk and potential impact, making continuous monitoring critical.

Irrigation efficiency represents a major reduction opportunity in this sector, and one that directly affects the owner’s bottom line. Unlike indoor water use, which is often metered and billed to residents, outdoor irrigation is typically the owner’s direct operating expense. For garden‑style communities with extensive landscaping, this cost exposure is significant, particularly in regions where water rates have risen sharply over the past decade. In a portfolio‑wide deployment spanning 19 states and 29 metropolitan markets, a national multifamily operator achieved 40–50% reductions in outdoor water demand using smart irrigation controls, as documented in this Alliance Residential Case Study. The portfolio included a mix of garden‑style and high-rise properties with diverse landscaping and climate conditions, and results were consistent across geographies, with some of the strongest savings occurring in wetter markets where the problem is less obvious, but just as costly when it goes unchecked. These are the kinds of measurable, sustained, portfolio-scale reductions that may support improved assessment outcomes and demonstrate progress over time.

Flow monitoring protects the water savings from improved irrigation efficiency. Across multifamily communities, HydroPoint data shows that continuous monitoring routinely uncovers leaks that would otherwise go unnoticed. Real-life examples range from a faulty irrigation valve flowing at 87 gallons per hour, to a running toilet producing 321 gallons per hour, to sustained flows exceeding 800 gallons per hour in a garden‑style property prior to repair. Without this visibility, a single undetected leak can quietly offset months of irrigation savings and drive unnecessary cost.

Retail properties, especially open-air shopping centers, are among the most irrigation‑intensive asset classes in commercial real estate. Outdoor water use can represent the majority of total consumption, particularly in landscaped centers located in drought‑prone regions. According to ENERGY STAR Portfolio Manager benchmarks, retail properties have a median water‑use intensity of approximately 5.2 gallons per square foot per year, with the middle range spanning roughly 3 to 9 gallons per square foot depending on climate, tenant mix, and landscape design. Because irrigation is both seasonal and highly variable, retail portfolios face elevated exposure to water‑stress conditions and tightening municipal restrictions.

Irrigation optimization is the largest controllable source of savings in this sector. Kite Realty Group achieved 30.8 million gallons in annual savings across retail and office assets through weather-based scheduling and improved visibility, demonstrating the scale of reduction possible when outdoor water management is a priority. For GRESB Participants, these documented irrigation savings can represent a clear path to demonstrating year‑over‑year performance improvement.

Flow monitoring provides the insurance that protects those gains. Retail environments, with large outdoor footprints and complex irrigation infrastructure, are prone to losses that compound quickly without continuous visibility. Examples from HydroPoint data include a broken main‑line coupling producing 4,000 gallons per hour, a lateral line leak running at nearly 6,900 gallons per hour, and stuck irrigation valves flowing at 925 gallons per hour. Even smaller issues, such as restroom fixtures running at 70–150 gallons per hour or roof‑mounted cooling systems leaking thousands of gallons before detection, can erode irrigation savings if left unidentified. Continuous monitoring ensures that the efficiency gains that contribute to GRESB performance are not undermined by hidden losses elsewhere on the property.

Office buildings exhibit a distinct water‑use profile, with cooling systems and landscaped campuses driving most of the consumption. According to EPA’s WaterSense at Work best management practices, cooling towers can account for 20–50% or more of a facility’s total water use. ENERGY STAR Portfolio Manager benchmarks place the median office water‑use intensity at approximately 14.5 gallons per square foot per year, with the middle range spanning roughly 8 to 29 gallons per square foot, reflecting the significant contribution of cooling infrastructure. Rising water costs and increasing regulatory scrutiny in major urban markets are making water management a growing component of operational risk.

Irrigation efficiency is the most direct path to reducing outdoor use for office campuses, particularly those with large, landscaped footprints. Weather‑based controls routinely deliver over 30% reductions in outdoor water use by eliminating overwatering, adjusting for precipitation, and identifying mechanical failures in real-time. At Hanover Page Mill, a LEED Platinum research campus in Silicon Valley, smart irrigation controls achieved a 55% reduction in outdoor water use while maintaining the drought‑tolerant landscape.

These reductions are measurable, repeatable, and aligned with indicators related to resource management, consumption reduction, and target setting in the GRESB Real Estate Assessment.

Flow monitoring protects those results by catching the losses that would otherwise go undetected, especially in office environments where low occupancy during evenings and weekends delays manual discovery. Reported HydroPoint cases include a cooling tower with a failed water‑level control wasting 331 gallons per hour, an irrigation valve that failed to close, generating 719 gallons per hour, and a main line break reaching 1,653 gallons per hour before detection. Without continuous visibility, these issues can persist for days or weeks, offsetting irrigation savings.

Water risk is rising across global real estate markets, but sector-specific intelligence enables more targeted, high-ROI action. Office, retail, and multifamily assets, representing the core of GRESB participation, each exhibit distinct water‑use drivers and reduction pathways. Senior Housing adds an important layer of intensity within the multifamily category, reinforcing the need for continuous monitoring and proactive management. 

By combining efficient irrigation with real‑time flow monitoring and anomaly detection, owners can reduce consumption, protect savings, and strengthen resilience, while providing the data transparency required for credible GRESB participation. 

U.S. Environmental Protection Agency. “What Is Water Use Intensity (WUI)?” ENERGY STAR Portfolio Manager. https://www.energystar.gov/buildings/benchmark/understand-metrics/what-water-use-intensity-wui 

U.S. Environmental Protection Agency. “WaterSense at Work: Best Management Practices, Section 6.3 — Cooling Towers.” https://www.epa.gov/system/files/documents/2023-05/ws-commercial-watersense-at-work_Section_6.3_Cooling_Towers.pdf

This article was written by Jemetha Clark, Chief of Staff, Growth and Impact at HydroPoint Data Systems. Learn more about HydroPoint here.