What is sub-metering?

The main meter tells you how much the building used. It does not tell you where. Sub-metering puts secondary meters downstream of that utility (or landlord supply) meter so electricity, gas, water or heat can be split by tenant, floor, riser or end use. You will also see sub metering and submetering; same practice. This page is commercial-building metering strategy and the data path into an EMS or BMS. It is not a shop for an electricity sub meter.

What a sub-meter measures vs the main meter

The main meter settles the supplier bill. A sub-meter does not take that job. It measures a slice: a tenant demise, a floor board, a chiller feed, a lighting distribution, a kitchen, a process line. Electricity is the usual case; gas, water and heat follow the same idea when those fuels matter. Without the split, year-on-year kWh and cost allocation stay blunt. With it, you can separate landlord plant from tenant plug load, and HVAC waste from lighting schedules.

Location metering vs end-use metering

Commercial estates usually mix two layouts. Location (area) metering covers a floor, wing or demise so cost and intensity follow space. End-use metering covers a system or plant item so HVAC, lighting and process can be managed on their own. Part L and CIBSE TM39 strategies often want both: enough area meters for allocation, enough plant meters for the loads that move the bill. Virtual or soft meters (calculated from other points) can fill gaps when hardware is missing; they are estimates, not custody-grade settlement. Explore can use virtual sensors beside real meter feeds. Treat them as supporting signals, not a stand-in for a calibrated sub-meter when you need hard allocation.

How readings leave the meter

A pulse output, Modbus register map, M-Bus telegram or BACnet object is how the number becomes a timeseries. Some meters sit on a dedicated AMR collector; others land in the BMS or a gateway. Interval matters. Half-hourly (or finer) electricity data is the working minimum for most monitoring and targeting. A register that only updates when someone walks the plant room is not a monitoring feed. Once the stream is continuous, an energy management system or Sensor Intelligence layer can baseline, flag drift and rank waste. FrostLogic Explore's Edge Agent speaks BACnet, OPC UA, Modbus, MQTT, M-Bus and oBIX for those feeds.

Why operators care (allocation, waste, evidence)

Fair tenant or department allocation needs measured slices, not floor-area guesses. Waste finding needs the same slices timed against schedules and weather. UK non-domestic Building Regulations Part L (Approved Document L Volume 2) expects end-use metering and data that can be read, with automatic meter reading guidance for larger buildings. Exact thresholds live in the current Approved Document, not here. CIBSE TM39 Building metering and monitoring (2026) is the current method guide for metering strategy in non-domestic buildings (the 2009 edition is archived). Explore is not an assessor, metering contractor or ESCo. It does not sell or install sub-meters. Meters and pulses you already have (or will fit with an electrician) become useful when someone reads them continuously.

Where Explore sits

FrostLogic Explore is Sensor Intelligence. It reads the meter and BMS stream and returns a prioritised decision queue via Frostdynamics™. It does not replace the meter, the billing system or the BMS that may already poll those points. Write access starts off; you grant scopes after review or auto-run inside a granted scope. The continuous meter path is energy monitoring in Explore. The wider commercial EMS framing is energy management software.