Sub Meters for Electric: A Property Owner's Guide
You're looking at one bulk hydro invoice for an entire building, while tenants ask why their charges don't reflect how much electricity they use. A suite with modest consumption can end up carrying part of a neighbour's heating, cooling, or appliance load, and the owner absorbs the difference when a flat allocation no longer covers the bill.
That's the practical reason sub meters for electric exist. They separate the building's total utility consumption into defensible, unit-level measurements, but they also introduce regulatory, installation, billing, and tenant-communication responsibilities. In Ontario, the question isn't whether a device can measure electricity. It's whether the device and billing arrangement meet the requirements for a licensed unit sub-metering program.
Table of Contents
- Why Electric Submetering Exists for Multi-Unit Properties
- What a Sub Meter for Electric Actually Does
- Main Types of Electric Submeters and How They Communicate
- Measurement Canada and Ontario Energy Board Standards Explained
- Financial Benefits and Conservation Impact for Owners
- Installation and Commissioning From Agreement to Live Meters
- Tenant Billing, Compliance, and Day-to-Day Operations
- Is Electric Submetering the Right Move for Your Building
Why Electric Submetering Exists for Multi-Unit Properties
A property owner with one master meter has one indisputable number: the building's total electricity consumption. The utility bills the property at the service entrance, but that bill doesn't show which suite consumed the electricity. Without unit-level data, the owner has to recover costs through rent, a flat utility fee, square-footage allocation, or another formula that may not match actual use.
That creates friction on both sides. Tenants question charges they can't verify, while owners carry the risk that a high-consuming suite will be subsidised by a lower-consuming one. The arrangement also weakens the behavioural signal. If a tenant's bill stays the same whether they run supplemental heat, leave windows open, or use more appliances, the tenant has little financial reason to change those habits.
The regulatory issue behind a technical upgrade
An owner can install a device that records electricity without automatically gaining the right to use those readings for tenant billing. Measurement Canada treats sub-metering devices used to establish charges as revenue meters, which is different from installing a non-revenue monitor for internal energy management. Ontario also requires licensing for unit sub-metering activity. The Ontario Energy Board's Unit Sub-Metering Code sets minimum conditions and standards for licensed providers.
Ontario's regulatory history is specific. Amendments to the Ontario Energy Board Act, 1998 came into force on April 1, 2018, giving the OEB authority to regulate rates charged by unit sub-meter providers. That rate-making authority was later repealed on April 3, 2019 through Bill 66, while the OEB continued to maintain the Unit Sub-Metering Code. The framework remains important because it connects licensing, consumer protection, standardized billing, and provider obligations.
Practical rule: Treat submetering as a regulated billing program with electrical hardware attached, not as a simple way to split one invoice.
The rest of the decision comes down to four questions. What type of meter suits the electrical layout? Which Measurement Canada and OEB requirements apply? Does the recovery and conservation case justify the work? And how will reads, invoices, notices, disputes, and maintenance operate after installation?
What a Sub Meter for Electric Actually Does
An electric submeter is a secondary meter installed downstream of the utility-owned bulk meter. It measures the electricity consumed by a defined load, usually an apartment, commercial unit, or separately served area. The utility's meter still records the building's total draw, while the submeters create the unit-level record used for allocation, analysis, or, where approved, tenant billing.
Consider a 24-suite mid-rise with one service entrance. The bulk meter records the property's total electricity use for the billing period. Each suite submeter records its own consumption, allowing the billing system to associate a measured quantity with a specific unit. Common areas must be identified separately rather than folded into resident consumption.
What the device can and cannot prove
A submeter can provide auditable consumption evidence when it's an approved revenue meter installed and sealed in an approved configuration. It isn't automatically a billing device because it displays kilowatt-hours. A load monitor, dashboard sensor, or non-revenue data logger may help an operator understand energy patterns, but those products don't necessarily establish a lawful tenant charge.
The distinction affects procurement. The owner must verify the meter's approval status, installation configuration, sealing process, read collection, and billing-party responsibilities before approving equipment. A technically accurate device can still be unsuitable for revenue billing if the complete configuration hasn't been approved for that use.
Attribute
Utility Bulk Meter
Electric Submeter
Primary role
Records the property's total electricity supplied by the utility
Records consumption for a defined suite or load
Ownership and control
Typically utility-controlled
Installed and managed within the submetering program
Billing relationship
Supports the utility's invoice to the property
Supports allocation, monitoring, or approved tenant billing
Measurement scope
Whole building or service entrance
Individual unit, commercial space, or selected load
Common-area visibility
Included in the building total
Requires separate design or dedicated common-area meters
Compliance significance
Utility revenue measurement
Revenue-grade requirements apply when readings establish charges
A useful test is simple: if the owner wants to send a tenant an invoice based on the reading, the meter must be evaluated as part of a regulated revenue-measurement chain. If the owner only wants operational visibility, different equipment may be appropriate, but it shouldn't be presented as billing evidence.
Main Types of Electric Submeters and How They Communicate
The electrical room and suite-panel layout usually matter more than the brand name. A new construction project can plan meter stacks, disconnects, wiring paths, and communications from the outset. An occupied retrofit has to work around existing panels, risers, access limits, and shutdown constraints.
Meter formats owners are commonly quoted
Direct-read CT meters use current transformers around conductors and provide a local reading. They can suit residential panels where staff or service personnel can access the equipment, but manual collection adds operational work and creates more opportunities for missed or inconsistent reads.
Split-core CT meters open around an existing conductor, which can simplify retrofits where the electrical system can't be fully de-energised. The split-core current transformer guide is useful for understanding why this format is often considered when panel access and shutdown planning are difficult. The trade-off is that installation quality, CT orientation, conductor identification, and configuration checks become especially important.
Multi-family meter stacks combine meters and breaker disconnects in a structured assembly. They're a natural fit for new construction or major electrical renewal, where the project team can coordinate equipment with the distribution design. They're less convenient when an occupied building has no suitable space or when the existing risers don't match the proposed arrangement.
Smart submeters add communications, automated reads, exception monitoring, and data access. They reduce manual handling and support tenant portals or recurring billing workflows, but they bring platform, gateway, cybersecurity, and service-dependency considerations.
Communication choices
Hardwired Modbus over RS-485 can be dependable in a mid-rise with accessible cable routes and a controlled network design. Wireless mesh can reduce cabling disruption in occupied buildings, although signal planning and device reachability need to be tested across electrical rooms and suites. Cellular or gateway-based cloud systems suit owners who want remote reads across a portfolio, but they add reliance on gateways, connectivity, software availability, and vendor support.
Submeter Type
Best Fit
Communication Options
Owner Trade-off
Direct-read CT
Accessible panels and simple operating models
Local reading, wired connection
Lower system complexity, higher manual effort
Split-core CT
Retrofit panels where shutdowns are constrained
Wired, wireless, or gateway
Easier physical installation, more commissioning attention
Meter stack
New construction or major electrical renewal
Wired network, building gateway
Clean design, limited retrofit flexibility
Smart submeter
Automated billing and portfolio reporting
RS-485, wireless mesh, cellular, cloud gateway
Better visibility, greater technology dependency
Communication choice doesn't replace certification. Only approved devices in approved configurations should drive tenant billing. The owner is selecting a billing-grade system, not just a sensor that happens to transmit data. Ask vendors to document the full meter, CT, communications, sealing, commissioning, and billing configuration before comparing quotations.
Measurement Canada and Ontario Energy Board Standards Explained
The pre-installation compliance review should happen before equipment is ordered. Measurement Canada's revenue-meter requirements and Ontario's unit sub-metering rules address different parts of the same practical question: can this arrangement support charges to occupants, and who is authorised to issue them?
Start with the meter
A device used to establish a charge for electricity as a commodity must be treated as a revenue meter. The owner should request documentation showing the device's approval status, applicable configuration, inspection and sealing process, and the records that will be retained. A non-revenue allocation meter may still help with internal analysis, but it shouldn't be used as the sole basis for a tenant commodity charge.
The OEB licensing and code materials state that no person may engage in unit sub-metering without a licence. Licensed providers must meet the Code's minimum standards, and a new licence requires an application fee plus an annual registration fee. That makes the identity and role of the billing entity a central part of the project, not an administrative detail to resolve after installation.
Use a documented verification sequence
- Confirm the measurement path. Identify every suite meter, common-area meter, CT, disconnect, gateway, and meter data relationship on the design.
- Verify approval and sealing. Ask who performs the inspection, how seals are documented, and what happens if a meter or CT must be replaced.
- Confirm the licensed billing entity. The party operating the unit sub-metering program must hold the required OEB licence or structure the service through an authorised licensed arrangement.
- Review tenant communications. Lease language, notices, effective dates, rate explanations, and dispute channels should be prepared before the first bill.
- Define records and audits. Establish who stores meter reads, invoices, exceptions, maintenance records, and evidence supporting adjustments.
Where U.S. projects differ
A U.S. property owner may deal primarily with a state public utility commission, state weights-and-measures authority, and technical standards such as ANSI C12.20. Those frameworks aren't interchangeable with Ontario's OEB licensing structure or Canadian revenue-meter process. A portfolio operating on both sides of the border should maintain a jurisdiction-specific approval matrix rather than assuming an approved U.S. device or billing model transfers automatically to Ontario.
Financial Benefits and Conservation Impact for Owners
The financial case is strongest when the owner can identify where electricity costs are currently being absorbed, allocated poorly, or left outside the recovery process. The Ontario evidence provides a concrete starting point. A Submetering Council of Ontario update reported 352,792 total units served and 588,475,056 kWh per year in conservation benefits across the province, showing that electric submetering operates at meaningful scale rather than as a niche experiment. The Ontario submetering data and analysis also reports results from earlier Ontario studies.
One analysis found that approximately 170,000 submetering customers paid an average of $66.52 per month with submetering, compared with $78.43 with individual metering by the local distribution company, a difference of $11.91 per month per customer. Another study found a 139 kWh per unit monthly decrease in electricity use during the first year after submetering, equal to a 40% reduction. It estimated that province-wide deployment in eligible multi-residential buildings could avoid $1.2 billion in electricity generation, transmission, and delivery costs over 20 years. Each figure applies to the cited Ontario analyses, not automatically to every building.
Where the owner sees value
NOI recovery comes from moving eligible tenant consumption through a documented billing chain rather than leaving all electricity inside rent or a broad common-cost pool. The benefit depends on the property's existing recovery method, electrical design, vacancy pattern, tariff, and permitted charges.
Conservation comes from giving residents information and financial responsibility for measured consumption. The Ontario study's reported first-year reduction indicates why the behavioural component can matter, but the result shouldn't be copied into a pro forma without checking the building's heating, cooling, and appliance profile.
Capital planning requires more discipline than a simple payback claim. Include panel work, electrical shutdowns, communications, inspections, tenant access, billing setup, ongoing service, and the treatment of common areas. A compliant system with weak collections or poor tenant communication can underperform even when the meters themselves work correctly.
Owner's test: Build the model from the building's actual master-meter history and recovery records. Use provincial evidence as context, not as a substitute for an asset-specific feasibility review.
Metric
Pre-Submetering Baseline
Post-Submetering Range
Owner Impact
Customer electricity charge in the cited Ontario analysis
$78.43 per month with individual LDC metering
$66.52 per month with submetering
$11.91 monthly difference per customer in that analysis
Unit electricity consumption in the cited Ontario study
Starting monthly usage before conversion
139 kWh per unit lower in the first year
Reported 40% reduction in that study
Ontario deployment scale
Buildings without unit-level billing data
352,792 units served in the cited update
Demonstrates substantial provincial adoption
Conservation benefit in the cited update
Consumption before reported conservation
588,475,056 kWh per year
Reported provincial conservation benefit
Long-term system impact estimate
Eligible multi-residential deployment without the intervention
Avoided costs over 20 years
$1.2 billion estimate in the cited Ontario study
Installation and Commissioning From Agreement to Live Meters
A submetering project becomes difficult when the proposal describes equipment but not the path to a billable read. The owner should expect a coordinated process involving the provider, electrical contractor, property manager, tenants, inspectors, and billing operator.
The project sequence
- Site survey and one-line review. The team maps service entrances, panels, risers, common areas, CT locations, communication routes, and access conditions.
- Scope lock. The proposal should identify the units included, common-area treatment, electrical work, communications, tenant notices, commissioning, maintenance, and billing responsibilities.
- Equipment verification and procurement. Meter approvals, configurations, lead times, and replacement procedures are confirmed before ordering.
- Access planning. The property manager coordinates suite entries, notices, keys, escorts, locked electrical rooms, and shutdown windows.
- Installation and testing. Electricians install meters and CTs, label circuits, verify polarity and phase relationships, and test communications.
- Inspection and sealing. The revenue-meter process is completed and documented before readings are used for charges.
- Billing registration and parallel run. The licensed billing entity maps meters to units, validates reads, checks exceptions, and prepares tenants for the first live invoice.
The schedule risk owners underestimate
Tenant access is usually the largest retrofit variable. Missed appointments, locked rooms, incomplete suite lists, and residents who aren't available can force return visits and disrupt the installation sequence. Electrically heated buildings and sites with difficult mechanical-room access add further coordination because the team must understand larger loads and shared services before finalising the design.
For a straightforward 50-suite retrofit, the provider may describe a 6 to 10 week path from agreement to live meters. Poor access coordination or scarce inspection availability can extend the project to 12 to 20 weeks, as documented in the project assumptions supplied for this guide. These are planning ranges, not guarantees.
Use the provider's utility metering installation and maintenance service to clarify what it handles. The owner still needs to appoint a responsive site contact, approve access notices, provide building drawings and utility history, coordinate property staff, and make decisions when concealed conditions change the scope.
Tenant Billing, Compliance, and Day-to-Day Operations
Once meters are live, the programme shifts from construction to monthly control. The billing operator receives automated reads through a communications network, validates missing or abnormal data, maps each read to the correct suite, applies the permitted rate structure, and issues invoices.
Ontario programs commonly need to distinguish the utility commodity charge, delivery components, taxes, and any permitted administration charge. The owner shouldn't assume that a convenient flat fee is acceptable because it's easy to explain. Where a charge is based on electricity consumption, the amount must be supported by the approved meter and the applicable rules. The billing arrangement also needs to avoid profiting from a commodity pass-through where the governing framework prohibits it.
A transparent operating workflow
- Read collection: AMI, cellular gateways, or another approved communication path transmits meter data to the billing platform.
- Exception review: The operator investigates missing reads, unusual consumption, reversed CTs, communication loss, and unit-status changes.
- Invoice generation: The system applies the approved tariff logic, identifies the billing period, and shows the measured consumption and charge components.
- Tenant access: A portal or clear invoice detail gives residents a way to understand usage rather than forcing them to accept an unexplained total.
- Collections and disputes: Late-payment handling, adjustments, complaint escalation, and records are managed under the lease, service agreement, and applicable landlord-tenant requirements.
The residential and commercial utility billing overview can help owners compare how unit-level billing needs differ between apartments, retail spaces, offices, and mixed-use properties. Commercial tenants often have different operating hours and load profiles, so a single residential assumption can distort the billing design.
Tenant relations are part of compliance
If electricity was previously included in rent and will become a separate metered charge, the property manager needs to handle notices, lease disclosures, effective dates, and legally required landlord-tenant board processes. Give residents a plain explanation of what the meter measures, how common areas are treated, where rates come from, and how to challenge a reading.
The owner should also retain meter records, invoices, corrections, maintenance documentation, tenant correspondence, and evidence supporting rate calculations. Automation reduces manual work, but it doesn't remove accountability. A clean monthly process is one where a manager can explain a disputed invoice without asking the electrician to reconstruct the installation from memory.
Is Electric Submetering the Right Move for Your Building
The strongest candidates are mid-to-large multi-unit properties with individually separable electrical loads, electrically heated or cooled suites, meaningful common-area consumption, or persistent exposure to a single bulk bill. Mixed-use properties can also benefit when residential and commercial loads are designed and billed separately.
The weaker candidates include small buildings where administration and installation effort outweigh recoverable value, properties with mostly shared central utilities, and jurisdictions with tight limits on electricity charge recovery. A submeter can produce excellent data and still fail as an investment if the electrical architecture is too complex, tenant access is unreliable, or the legal billing model doesn't support the intended recovery.
Use a simple decision process:
- Go: The building has separable loads, a compliant billing path, reliable access, and a clear gap between electricity cost and current recovery.
- Conditional go: The opportunity is credible, but the owner needs design validation, tenant-notice planning, or multiple quotes before committing.
- No go: Shared loads dominate, the jurisdiction restricts the proposed pass-through, or the financial model doesn't support the required capital and administration.
Commission a feasibility assessment, request a Measurement Canada approval review, obtain three installation quotes, and model the five-year NOI effect using the building's own bills and recovery records. Axis Meter Solutions offers turnkey electricity submetering, including Measurement Canada-aligned equipment, installation, commissioning, tenant billing, and ongoing maintenance for Canadian and U.S. properties. Visit Axis Meter Solutions to discuss the electrical layout, compliance pathway, and a property-specific submetering plan.
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