How Commercial Buildings Can Investigate Unexplained Water Loss

Start with the data

Gather at least 12 months of bills and, if available, meter reads. Convert cost to volume, and compare like months. Then find the building's minimum night flow: a meter read late at night (or logger data) showing continuous use when the building is empty is the strongest single indicator of a real loss.

• Usage volume, not just cost
• Night flow / minimum flow
• Occupancy or process changes that explain increases

Build a water balance

List the legitimate uses — sanitation, kitchens, cooling, irrigation, process — and estimate each. The gap between metered use and accounted use is the unexplained loss, and its size decides how hard to hunt. An office building water audit formalises this step; a loss survey takes it further, into the pipework.

Isolate by zone

Use the building's valves and any sub-meters to divide it into zones: floors, risers, wings, irrigation, mechanical. Isolate one zone at a time (out of hours where needed) and watch the meter. The zone whose isolation stops the loss becomes the search area — the building has been narrowed from acres of pipe to a floor or a riser.

Pinpoint and document

Within the guilty zone, acoustic surveys of accessible pipework, fixture checks and pressure testing locate the loss. Document everything: readings, zones tested, the finding, and photographs. Documentation is what turns a repair into a defensible cost for owners, and evidence if insurers or tenants are involved.

Common commercial culprits

The unglamorous list causes most commercial loss: silently running toilets across many restrooms, stuck irrigation valves, cooling-tower overflow faults, underground service leaks, and fixtures left passing water in little-used areas. The zone process finds them because it measures rather than assumes.

Frequently asked questions

Need help with this at your property? See Commercial Water Loss Surveys or request leak detection service.