What is tenant billing?

The mechanics

In most multi-tenant buildings, utility cost is recovered through a common-area maintenance charge allocated by rentable square footage. That works when consumption is proportional to floor area. It stops working the moment it isn't — and it usually isn't.

Plug and process loads are around 33% of an office building's energy and are projected to rise 49% by 2030 (NREL). Those are exactly the loads that vary most between tenants and least with floor area: a trading floor, a data closet, a commercial kitchen, a tenant running two shifts in a building leased as single-shift. Under square-footage allocation, the low-intensity tenants subsidise the high-intensity ones, and the landlord absorbs whatever the recovery formula fails to capture.

Tenant billing replaces that with measurement. Four allocation methods dominate:

• Direct metering — the utility bills the tenant directly. Cleanest and rarely available in an existing building's electrical topology.
• Submetered billing — the landlord meters each premises and rebills. The subject of this page.
• Cost allocation / chargeback — internal apportionment between departments or cost centres, with no external invoice. A lower legal bar entirely.
• Pro-rata with a measured adjustment — square footage as the base, with a measured true-up for identified high-intensity loads.

The binding constraint is legal, not technical

This is the single most important fact about tenant billing, and it is why resolution is irrelevant to it. The required data resolution is monthly kilowatt-hours. Nobody's lease is billed at one-minute resolution. Interval data is needed only where the allocation is time-of-use or demand-weighted.

What is not optional is the legal standing of the measurement:

| Jurisdiction | Requirement | |---|---|---| | California | CTEP certification for submeters used in billing | | New York | ANSI C12.20-compliant equipment; residential submetering requires a PSC petition, typically 6–8 months | | Maryland | PSC-approved ANSI-compliant meters, with a mandatory bill adjustment if a submeter is found more than 2% fast or slow | | Many states | Submetering permitted with NEC compliance and no specific certification mandate |

Certification covers the whole measurement chain, including the current transformers, not just the meter body. This is why the two-grade distinction is not negotiable:

• Billing grade — externally powered meters with their own voltage reference and metering-class CTs, on billing boundaries only, mapped to the jurisdiction before hardware is quoted.
• Insight grade — self-powered wireless sensors everywhere downstream, explicitly not for billing. GSA measured this class at 7% average energy error, from 52% under to 38% over depending on load type, against its own ±0.5% revenue-grade definition and ±2% billing threshold.

Any vendor claiming "revenue grade" for a self-powered wireless current sensor without naming the CT and the type approval is making an unsupported claim, and the place it surfaces is a chargeback dispute two years into a lease.

Worked example: why this is a balance-sheet event, not an expense line

Tenant billing is the only facility-energy outcome that converts an operating improvement into asset value, because recovered utility expense flows dollar-for-dollar to net operating income, and net operating income capitalises.

A 150,000 sq ft, 20-tenant building where measured allocation recovers $25,000 a year that the landlord was absorbing:

Annual expense recovered	@ 6.0% cap	@ 7.0% cap	@ 8.0% cap
$25,000	$417,000	$357,000	$313,000
$50,000	$833,000	$714,000	$625,000
$100,000	$1,667,000	$1,429,000	$1,250,000

At $1,500–$2,000 per billing-grade submeter, a 40-space industrial park is a $60,000–$80,000 hardware spend against a six-to-seven-figure valuation swing.

The arithmetic survives diligence because the only two inputs are the owner's own recovery delta and the owner's own cap rate. It is worth being direct about the limit: there is no strong independent ROI study for commercial submetering. The arithmetic is the case; a borrowed case study is not.

The operational details that decide whether it works

• The lease has to permit it. A lease written for square-footage allocation does not become a submetered lease because a meter was installed. Most portfolios convert on renewal, which means a multi-year transition and two allocation methods running in parallel.
• The lease-to-premise-to-meter map needs effective dates. A tenant expanding into an adjacent suite mid-term silently corrupts six months of invoices unless the map is versioned.
• Reconcile to the utility bill every cycle. The sum of tenant meters plus house load should reconcile against the bill being allocated, with the residual shown. A residual that grows is how an unbilled load or a stale meter constant gets found.
• Every invoice must be traceable to the raw reads behind it, including which intervals were estimated and by which method. This is what a tenant's controller will ask for, and the answer decides whether the programme survives the first challenge.
• The lag is real. Average time between the end of a billing period and cost recovery today is 30–45 days, and it is manual work in most buildings. And 70% of tenants report worrying more about escalating utility bills than about rising rent — which is an argument for transparency, not against measurement.

What tenant billing is not

It is not the same as submetering. Submetering is measurement. Tenant billing is a legal and commercial process built on top of it, governed by state utility law and by the lease. A submeter is necessary and nowhere near sufficient. See what is submetering.

It is not reselling electricity. In most jurisdictions a landlord may recover measured cost but may not profit on the resale of energy, and some states cap the rate at the landlord's own blended cost. The distinction is a legal one and it varies by state.

It is not a technical problem solved by better resolution. Ten-second data does not make an uncertified meter legal for billing. The constraints here are certification, jurisdiction and lease language, and none of them is improved by more samples.

It is not the same as internal chargeback. Allocating cost between departments, lines or cost centres runs perfectly well on insight-grade sensors at ±2–5% accuracy, with no certification requirement, because no external invoice is issued. That distinction belongs in the contract, not buried in a footnote.

Asset managers do not buy "submetering". They buy tenant recovery, cost allocation and chargeback — which are the same measurement described as the outcome it produces.