How Water Submetering Systems Work: Meters, Reading, and Billing

What a water submetering system is

Most older multifamily properties rely on a single city water meter. The municipality tracks total property consumption, bills you directly, and leaves you stuck with the bill. You have no way to know which resident wastes water and who conserves it. In a master-metered building, rising water rates eventually push rent up because the owner has nowhere else to put the cost.

Submetering introduces private meters downstream from the main utility connection. A meter goes directly on the incoming cold supply, or on both the hot and cold lines if your pipe layout requires it. That setup tracks only the water consumed inside that specific apartment or home.

These setups never replace the city meter. The local utility bills you for total site use just like before. Submeters simply provide the numbers to allocate costs based on true individual use. Common-area water (laundry, irrigation, pool) is measured separately and stays with the owner, and the total billed to residents never exceeds the property's actual master-meter water cost.

The parts of a water submetering system

A working setup relies on several connected pieces of submetering equipment, and a failure at any stage disrupts your billing.

From faucet to bill: how water submetering systems work, step by step

Here is how a single gallon travels from the tap to an itemized invoice.

1. 1A resident washes dishes, runs the laundry or flushes a toilet, drawing water directly through the unit's meter.
2. 2The meter measures that volume and transmits a signal to its connected radio unit.
3. 3The transmitter sends out an updated consumption reading over the air, several times a day.
4. 4Where your property needs them, repeaters relay the radio signal to the on-site gateway.
5. 5The gateway packages every incoming read and pushes the batch to the billing platform via cellular network.
6. 6The billing platform scans the data for issues like stopped meters and applies your rates.
7. 7Residents get an itemized statement detailing their consumption and charges, sent by mail or posted to an online portal.

How meters are read

Your method for reading meters matters just as much as the hardware. Traditional methods still count on a person walking the property.

If you only read meters once a month, a running toilet turns into an ugly surprise after gallons have already poured down the drain. Modern systems transmit several times a day, giving you apartment leak detection that spots failed equipment or hidden leaks within a day. That lets you dispatch maintenance instead of explaining a massive bill.

NES provides daily leak tracking through the MyReads portal. The system highlights continuous overnight flow, which is the usual sign of a running toilet or a leak, so your maintenance crew can fix it fast.

What a water submetering system costs

Planning a budget for submetering comes down to three basic expenses:

1. 1Installation. Plumbing labor to splice each water line, install meters, mount wireless transmitters and configure the network.
2. 2Equipment. Physical equipment including meters, radio transmitters, signal repeaters and the cellular gateway.
3. 3Monthly billing fee. Monthly service charges covering meter reading, resident billing, account support and property reports.

Installation averages $150 to $300 per unit. The water submeter installation cost for your property can change based on the factors below:

• How many meters each unit needs.
• The meter type.
• Whether meters go indoors or outdoors.
• Whether your property is new construction or a retrofit.
• How easy each unit's water line is to reach.
• Whether NES installs or supplies equipment for your own plumber.

Pipe access drives installation cost more than anything else. An open pipe in a utility closet makes for quick work. Pulling out a water heater to reach the connection requires extra labor and pushes the cost up. That is why individual unit costs can vary on the same property.

Payback is where the numbers get interesting. Most properties earn back the install cost in 12 to 18 months from recovered water expenses, and some see it sooner. That recovery continues every year after that. Your actual result depends on your current water bills and rates, which is why NES prices from your actual bills rather than general assumptions. You can check the numbers yourself with our online ROI calculator.

Take a real example from NES property records. A 337-unit apartment community shifted water responsibility to residents based on individual meter data. Average consumption dropped 34%, falling from 5,846 to 3,868 gallons per unit per month. The average water cost per unit fell from $84.72 to $54.22 a month. That 36% drop saved about $30 per unit per month, adding up to roughly $123,000 a year for the community. This is one property, not a promise.

What installation looks like

Owners often delay projects out of concern over site disruption. In reality, a planned submeter installation moves quickly. Total time depends on your building count, property layout and line access. Equipment and resident billing are usually live within a few weeks to about 90 days, depending on the property, and NES provides a schedule once the site survey wraps up.

1. 1Site survey. A technician surveys pipe configurations, potential meter locations, plumbing access points and radio signal paths across your property.
2. 2Resident notice. Your office alerts residents ahead of scheduled work so everyone knows when crews are on site. Water service shuts off only briefly while plumbers cut the meter into the supply line.
3. 3Meter installation. When the line is easy to reach, a meter goes in in under 30 minutes, and the plumber needs a space about the size of a football to fit it. Water to the unit is off only during that work, and NES can handle the installation or supply equipment for your own plumber.
4. 4Network setup. Repeaters go in where the property needs them and the gateway is powered up. Your maintenance team can often mount both. Each meter is checked to confirm it transmits an accurate starting reading.
5. 5Test period and first bills. We monitor incoming reads until signals stabilize so no one gets billed on incomplete data. Once confirmed, residents receive their initial statements.

Rules and resident communication

Submetering and billing rules vary by state and city, and some states require registration with agencies like the Texas PUC (opens in a new tab) or the North Carolina Utilities Commission (opens in a new tab). NES checks the rules for your exact address before quoting so you know what is allowed. See our guides for submetering in Texas and submetering in North Carolina to review state rules in detail.

Residents accept utility billing much better when communication is clear from the start. Provide written notice well before the first cycle and have every resident sign a utility addendum explaining the terms. When residents understand the process up front, your leasing office avoids angry phone calls.

Submetering or RUBS

Physical meters are not always practical for every property. In some buildings, the plumbing makes reaching each unit's line too hard or too costly, or the budget is tight. In those situations, ratio utility billing offers an alternative by dividing master bills through formulas based on unit square footage or occupant count, with virtually zero upfront setup cost.

The catch with RUBS is that it measures nothing. A resident away on business pays by the same formula as a neighbor running water all day, which weakens fairness and reduces conservation incentives. RUBS is also not allowed everywhere. NES handles both options and helps you choose what fits your layout, budget and local rules. You can weigh the options with our RUBS vs submetering calculator.

Questions to ask before you choose a submetering company

Any provider you interview should answer these questions directly.

• Who owns the meters? Choose nonproprietary meters that you own, backed by a warranty, so you are never locked in to a single billing company. With proprietary hardware, switching providers can mean replacing every meter on the property.
• How often are meters read? Monthly manual reads keep you blind to plumbing issues until the damage is done. Ask for an automated system that transmits readings several times a day.
• Do you offer leak alerts? Confirm the system sends daily alerts for continuous night flow so your team fixes a running toilet before the bill spikes.
• Who answers resident calls? Your on-site staff has enough to do without fielding utility calls. NES manages the entire workflow in-house, including installation, meter reading, resident billing and bilingual customer support.
• What are all the fees? Ask for an itemized breakdown that separates equipment costs, physical installation charges and monthly billing fees.
• What does the warranty cover? Review the separate warranty coverages for meters and transmitters, and clarify how quickly replacement parts get supplied if hardware fails.
• How do you handle state and local rules? Make sure the provider reviews local ordinances and utility commission registration requirements for your property address before quoting.

Related questions

• How much does submetering cost?
• Are submeters accurate?
• Submetering vs RUBS
• RUBS vs submetering calculator