Reducing Water Consumption by 70% in a Multi-Unit Residential Building

A Sub-Metering Case Study

By Erik Kalm  |  LinkedIn

Introduction

For the owner of a 25 unit rental building in Ontario, rising water costs had become an increasingly serious operational challenge. Between 2022 and 2024, annual water expenses climbed from $9,400 to $25,000, despite stable occupancy and no major plumbing work. Traditional leak detection produced no clear explanation. Bringing those costs under control had become a priority.

The owner partnered with Alliance Metering to install suite level water sub-meters throughout the building. For the first time, water consumption could be measured and controlled at the individual unit level rather than only at the building’s main meter. Residents became responsible for the water they actually consumed, creating accountability and a direct financial incentive to conserve water and address leaks promptly.

The results were significant. Within five months of implementation, measured water consumption declined by approximately 70 percent. Annual water costs fell by approximately 72 percent, from $25,000 to $7,100.

Perhaps most remarkably, the project did not simply offset rising costs. Despite substantial increases in both municipal water rates and water consumption, annual water costs ultimately fell below the building’s 2022 level.

The improvement was not the result of a single major repair. It was the cumulative effect of better information, individual accountability, and hundreds of small decisions made by residents. Collectively, it reduced water consumption by approximately 70 percent.

How It Worked

Alliance Metering installed hot and cold water sub-meters in every suite, 52 meters in total, serving two supply lines per unit. During the retrofit, the building’s plumbing was converted from a series, daisy chained configuration to a parallel layout. The new design improved measurement accuracy, simplified future servicing, and provided more consistent water flow throughout the building.

Each meter was connected to Alliance Metering’s remote reading network, allowing water consumption to be monitored continuously. Instead of waiting for the next municipal bill or relying on a resident to report a problem, unusual consumption patterns could be identified quickly. Running toilets, leaking faucets, and failing plumbing components that might otherwise continue for weeks or months became visible and could be addressed before they generated substantial costs.

The technology, however, was only part of the solution. The greater change was that responsibility for water consumption moved from the building as a whole to the individual suite. Residents became responsible for the water they actually consumed, creating accountability and a direct financial incentive to conserve water and address leaks promptly.

Successful implementation also depended on careful planning. Access to suites had to be coordinated, residents needed to be informed of the work being performed, and cabinetry and walls had to be restored following installation. Pets, scheduling conflicts, and privacy concerns all had to be accommodated. Like any successful retrofit project, the technical work was only part of the job. The customer experience mattered just as much.

The value of Sub-Metering is often seen as a billing system. In practice, its greatest benefit is operational. It transforms water from a shared and largely unmanageable expense into a controllable operating cost, providing both owners and residents with the information and incentives needed to reduce consumption.

Benefits Beyond Lower Water Bills

The reduction in water consumption was the most visible result of the project, but it was not the only one. The operational benefits proved to be just as significant.

• Fairness: Residents become responsible for the water they actually consume rather than sharing the cost of excessive usage by others.
• Cost Control: Owners gain a practical tool for controlling one of the building’s operating expenses by identifying trends, monitoring repairs, and measuring financial impact.
• Rapid Leak Detection: Continuous monitoring allows abnormal consumption to be identified quickly so problems can be corrected before they generate substantial costs.
• Better Maintenance: Consumption data allows maintenance efforts to be directed to the individual suite where the issue exists rather than searching the entire building.
• Better Conversations: Accurate information improves communication between owners, managers, and residents because discussions are based on measured consumption rather than assumptions.
• Environmental Benefits: Reduced consumption lowers demand on municipal infrastructure and domestic hot water systems while conserving an increasingly valuable resource.

Lessons Learned

Plan early. Include lease provisions, communication plans, access requirements, and scheduling before work begins.

Communicate clearly. Residents are far more likely to support a project when they understand why it is being undertaken and how it will affect them.

Address small problems while access is available. Replacing worn valves, toilet flappers, shower cartridges, and similar components during installation can avoid much larger costs later.

Respond quickly. Continuous flow alerts should never be ignored because early intervention is almost always the least expensive solution.

Measure net results. Gross savings alone do not tell the story. Tenant recoveries, billing costs, rent adjustments, and operating expenses all affect the final outcome. The figure that ultimately matters is the improvement in net operating income.

Conclusion

Sub-Metering is often seen as a billing system. I see it as an effective cost control system. The technology itself is straightforward. The real innovation is aligning responsibility with consumption.

One thing I have observed from the thousands upon thousands of one on one educational sessions I have conducted over the course of my career is that most people do not waste water because they are wasteful. They simply do not understand the impact of their choices. A running toilet, a dripping faucet, or a few extra minutes in the shower may seem insignificant to an individual resident. Across an entire building, however, those small decisions become substantial operating costs.

Sub-Metering changes that relationship. By aligning responsibility with consumption, it brings the interests of the owner and the resident closer together. The resident benefits by controlling their own costs. The owner benefits by controlling one of the building’s largest operating expenses. Both benefit from reducing waste and addressing problems promptly.

The improvement achieved in this building was not the result of a single major repair. It was the cumulative effect of better information, individual accountability, and hundreds of small decisions made by residents every day. Individually, those decisions were small. Collectively, they transformed the operation and costs of an entire building.

For the full case study, please visit:
https://alliancemetering.com/water-meters-case-study/