Sub-metering with LoRaWAN or wM-Bus.

What is sub-metering?

Sub-metering is measuring consumption per unit behind a building’s main meter. The utility bills the building from the main meter at the inlet. Apartment, tenant or area meters behind it show how that bill divides between the units that actually used the water, heat or electricity. Housing co-ops use it to bill residents fairly, and commercial buildings use it to recharge tenants or track consumption per event, floor or area.

Automatic readings make it easier to compare the main meter and individual units over the same period. That comparison helps identify missing readings, shared consumption and possible leaks. The resulting consumption data feeds Divako Settlement, where agreed rules determine each unit’s share of the building’s costs.

LoRaWAN or wM-Bus for sub-metering?

We recommend both LoRaWAN and wM-Bus for sub-metering. The right choice depends on the meters, the building and how often readings are needed. Both can supply the same allocation and billing workflow in Divako.

• wM-Bus: a suitable option for new installations and for keeping compatible meters already in place. A gateway collects the meters’ radio messages and forwards the readings to Divako. Check supported meter models, radio modes and encryption keys during planning.
• LoRaWAN: a suitable option for apartment meters and deployments that also connect other building sensors. Gateways forward meter messages through the LoRaWAN network to Divako. Check coverage where the meters are installed and select a reading interval that fits the use case.
• Both in one building: keep compatible meters and add either technology as the site develops. Divako brings the readings together for monitoring, main-meter comparisons and settlement.

See both approaches in practice: Leangen Løkka uses LoRaWAN for 143 apartments, while Unibet Arena uses wM-Bus for water and electricity readings.

From sub-meter readings to cost allocation and billing

Sub-metering provides consumption per unit. Divako Settlement combines those readings with supplier bills and allocation rules to calculate what each apartment or tenant owes. The radio technology used to collect a reading does not determine how the cost is divided.

1. Allocate costs. Use metered consumption, floor area, ownership shares or another agreed basis for each cost category. Account for common areas and main-meter differences explicitly. Explore the cost-allocation engine.
2. Keep your billing system or generate documents. Export per-unit allocations to your existing system, or produce bills and consumption statements in your own branding.
3. Add invoicing and payments when needed. Use the optional workflow for numbered invoices, delivery, payment matching and reminders. See invoicing and payments.

Each allocated amount can be traced back to the readings and the rule that produced it, helping property managers explain charges to residents and tenants. Explore Divako Settlement to choose the parts of the workflow your building needs.

How it works on Divako

1. Meter. Each unit has a water meter, a heat meter or heat cost allocators, and electricity meters where needed. Every device is registered to its apartment or tenant with a profile from the device library, so its readings are understood from the first message.
2. Network. The meters transmit over LoRaWAN or wM-Bus, with gateways selected for the chosen protocol. Gateway count and placement depend on coverage in stairwells, shafts and basements. Sameie Leangen Løkka runs 143 apartments on a single LoRaWAN gateway.
3. Platform. Readings are decoded, checked for gaps and implausible values, and aligned to a common timestamp with the main meter. The balance between the building’s intake and the sum of the units is visible per period.
4. Alerts. Continuous flow, reverse flow and meters that stop counting are flagged as the readings arrive. At Unibet Arena in Tallinn, potential leaks surfaced within two weeks of the wM-Bus network going live.
5. Settlement. Readings and supplier bills feed the agreed cost-allocation rules. Export each unit’s share to the existing billing system or add documents, invoicing and payments through Divako Settlement. Residents can see their own consumption in the app.

What to watch out for

• Agree the distribution rules before the first settlement. How the shared costs, the main-meter difference and vacant units are divided is a board decision, not a software setting. Write it down, and have the system apply it the same way every period.
• Read the units and the main meter at the same time. A balance between readings taken on different days measures the calendar, not the building. Use the main meter’s reading time as the reference for every unit.
• Plan for heat and hot water before 2027. Meters and heat cost allocators for heating and domestic hot water must be remotely readable by 1 January 2027. A system chosen only for cold water can become a dead end when the heat meters have to join.
• Check coverage in the basement, not in the hallway. Meters often sit in shafts, cabinets or basements where the signal is weakest. Place the gateway from where the meters are, and check the signal after installation.

Sub-metering in Norway

In Norway, housing associations and condominiums get sub-metering from Divako ENIQ, a Norwegian company built on the Divako platform. Divako ENIQ installs the meters, runs the cost allocation and invoices each apartment. In every other European country, Divako delivers sub-metering directly.