Utility double-billing happens when a tenant is billed directly for electricity or water and also shares the same cost through the CAM pool. Here's how to find it.
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Find My OverchargesSee a sample report firstUtility double-billing is what happens when a tenant is billed directly for a utility, electricity, water, gas, HVAC, and that same cost also appears in the CAM pool and gets allocated back to the tenant through their pro-rata share. The tenant pays twice for the same usage.
This is distinct from situations where a tenant simply pays high utility costs in CAM. The double-billing problem is structural: the same dollars are flowing through two billing channels simultaneously. It is most common in buildings where some spaces are individually metered and others are on a master meter, or where sub-metering was implemented partially and the accounting system was not updated to reflect the split.
The most common pattern: a building is initially on a master meter for electricity. The landlord installs individual sub-meters to allow direct billing of high-usage tenants, restaurants, medical offices, data-intensive businesses. The tenant begins receiving direct electricity bills. But the landlord's accounting system continues to include the whole building's electricity cost in the CAM pool, including the usage that is now being billed directly.
The tenant then pays their electric bill plus their pro-rata share of the utility CAM line item. The portion of the CAM utility allocation that corresponds to the tenant's directly billed usage is a double charge.
BOMA's Green Lease Guide addresses this explicitly, including in its model exclusion language: "special services and utilities separately chargeable to individual tenants" are excluded from the common area operating expense pool. ICSC retail CAM forms similarly exclude costs that are "separately chargeable" to a specific tenant under their lease terms.
Even without double-billing, the allocation method can produce overcharges. If common area utilities are divided equally among all tenants (per-tenant allocation) rather than proportionally by square footage, small tenants subsidize large tenants. A 1,000 square foot tenant sharing utilities equally with a 15,000 square foot anchor is paying a 15x larger share per square foot than they should.
Most NNN leases allocate operating expenses on a pro-rata basis, by square footage. If the landlord uses a different methodology for a specific category (such as per-meter or per-tenant), it needs explicit lease authorization. An undisclosed change in methodology is a billing error regardless of whether it results in an overcharge or undercharge.
Buildings with shared HVAC systems, a central plant serving both common areas and tenant spaces, are prone to allocation disputes. The total cost of running the central plant includes both the common area portion and the portion attributable to individual tenant HVAC loads. Without sub-metering or documented engineering estimates for the split, the landlord's allocation methodology is not verifiable.
If a restaurant tenant's commercial kitchen exhaust system or walk-in cooler loads are being run off the building's central HVAC and those costs appear in the common area CAM pool, that tenant's direct-use costs are being shared with tenants who derive no benefit from the restaurant's HVAC needs.
The U.S. Energy Information Administration's Commercial Buildings Energy Consumption Survey (CBECS) provides national electricity expenditure intensity estimates. In the 2012 CBECS data (released May 2016), the reported electricity expenditure for enclosed and strip malls was approximately $2.02 per square foot annually for electricity alone. At that rate, a 10,000 square foot tenant in a center with 100,000 square feet of occupied space would have a pro-rata share of roughly $2,020 per year in electricity costs, just for their share of common area electric usage.
If the building also includes their directly sub-metered usage (which might run $8,000-$15,000/year depending on the tenant type), and the CAM pool includes both, the direct portion represents a meaningful double-charge at scale.
These CBECS figures are from 2012 and reflect pre-pandemic energy pricing, but they illustrate the magnitude of utility costs flowing through commercial buildings even in a lower-cost era.
A strip center has 10 tenants. Common area utilities (parking lot lighting, signage, security systems) total $24,000 per year. This is a legitimate CAM charge divided pro-rata by square footage.
The center also has three tenants who are sub-metered for electricity. Their annual direct electricity bills total $38,000.
The building's total master meter electricity cost is $62,000 ($24,000 common area + $38,000 sub-metered tenant usage). The landlord includes the full $62,000 in the CAM pool because the accounting system has not been updated to exclude the sub-metered amounts.
A tenant with a 6% pro-rata share pays:
But the CAM utility share should only be based on the $24,000 in common area costs: $24,000 × 6% = $1,440.
Double-billing overcharge: $3,720 − $1,440 = $2,280 per year.
Over 5 years, assuming flat costs and consistent sub-metering, the recoverable amount is approximately $11,400.
Determine whether your space is individually metered or sub-metered for any utility. Check your lease and your utility bills, if you receive a utility bill from the landlord or the utility company, your space has separate metering.
Pull the utility line items from the CAM reconciliation with descriptions. Common area electricity, gas, and water are legitimate; metered tenant usage should not appear.
Compare the total utility costs in the CAM pool to the metering structure. If the building has 10 tenants and 4 are sub-metered, the CAM pool should exclude the sub-metered portion.
Request the utility invoices and any sub-metering records for the reconciliation period. Verify that the CAM pool reflects only common area usage.
Check the allocation methodology. Is it pro-rata by square footage? If not, what methodology is used and where is it authorized in the lease?
For HVAC, ask whether the system serves both common areas and tenant spaces. If so, request the documentation of how costs are split between the two.
If the utility account is in your name and you pay the utility directly, that is as strong as it gets. Verify that the CAM pool does not include utilities for spaces metered in individual tenant names. Request the utility ledger showing which meters are included in the pool.
Yes. The same double-billing structure can occur with water (sub-metered for high-use tenants like restaurants or car washes), natural gas, and shared HVAC steam or chilled water. The analysis is the same: identify whether the utility is separately billed to the tenant, then verify whether it is also in the CAM pool.
Exact prevalence statistics are not publicly available from BOMA or ICSC for this specific error type. Sub-metering is more common in newer developments and high-use-tenant buildings. In older shopping centers with master-metered electrical systems where sub-metering was retrofitted, the risk is higher because the accounting update is often incomplete.
Request documentation of the netting calculation. "It's handled internally" is not an acceptable answer to an audit question. The reconciliation should show either (a) utility costs net of sub-metered recoveries, or (b) gross utility costs with a separate line for sub-metered credits. If the netting is not visible in the reconciliation, you cannot verify it occurred.
Yes, within the applicable audit window and limitations period. Utility cost data and metering records are typically retained by property managers and utility companies for several years. The documentation request should specify the coverage period.
CAMAudit identifies utility line items in the CAM pool and cross-references them against your lease's direct-pay provisions. If your lease requires separate utility billing and the CAM pool includes costs that should be excluded, the system flags the double-billing and calculates your share of the overcharge.
See also: The CAM Overcharge Detection Playbook, all 12 detection rules with worked examples.
Related: Property tax overallocation in CAM statements | Common area misclassification overcharges