A mixed-use property runs two utility billing systems under one roof at the same time. The residential side typically uses RUBS or submetering. The commercial side runs on common area maintenance (CAM) charges and net lease pass-throughs. Most of the operational risk in mixed-use utility billing comes from letting those two systems bleed into each other, and Billee keeps them separated the same way it manages any other hybrid billing model.

Key takeaways

• Residential and commercial space in a mixed-use property need different utility billing methods: RUBS or submetering for residents, CAM allocation for commercial tenants.
• Commercial and residential customers pay different utility rates. The U.S. Energy Information Administration reported a national average residential electricity price of 16.48 cents per kWh in 2024, versus 12.75 cents per kWh for commercial, a 3.73 cent gap.
• CAM charges commonly absorb shared utility costs like lobby lighting and irrigation water, allocated to commercial tenants by pro rata square footage rather than RUBS math.
• A master meter that spans both residential and commercial space blurs consumption between the two, which is why cities like New York run formal processes to physically separate commercial billing from residential meters in mixed-use buildings.
• State RUBS statutes govern residential leases. They do not extend to commercial space, which is billed through CAM and net lease terms instead.

Why Utility Billing Works Differently in Mixed-Use Properties

A mixed-use property is not one billing problem. It is two billing problems that happen to share a building, a roof, and often a set of utility meters.

Residential and commercial sides need entirely different billing methods

The residential portion of a mixed-use property bills the way any apartment community does: RUBS or submetering, governed by state disclosure rules. The commercial portion, a ground-floor restaurant or a retail suite, bills through the commercial lease itself. Utilities show up as part of CAM charges or a net lease pass-through, calculated by pro rata leased square footage rather than RUBS formulas.

Operators who apply one allocation logic across the whole property, residential math to commercial space or vice versa, create billing that neither side's lease actually supports.

Commercial tenants pay different utility rates than residential ones

Residential and commercial customers are billed at different utility rate classes, and the gap is real money. The EIA reported a 2024 national average residential electricity price of 16.48 cents per kWh, compared to 12.75 cents per kWh for commercial customers.

If a mixed-use building runs on one blended utility account, that rate class mismatch can distort recovery on both sides of the property. Getting the allocation right starts with knowing which rate class actually applies to which square footage.

CAM charges quietly absorb shared utility costs

Lobby lighting, common-area electricity, and irrigation water for shared landscaping commonly get folded into CAM charges rather than tracked as a distinct utility line item. JPMorgan's overview of CAM structures describes the standard method: divide a commercial tenant's leased square footage by the building's total leasable space to set their pro rata share.

That math works fine for maintenance and janitorial costs. It works poorly for utilities, where actual consumption rarely tracks square footage cleanly, especially when a restaurant tenant's kitchen equipment draws far more power than an equivalent footprint of retail space.

Master meters blur the residential and commercial line

Without physical separation, one master meter captures a restaurant's walk-in cooler and a resident's studio apartment on the same bill. New York City's Department of Environmental Protection runs a formal application process specifically to split commercial consumption out of a mixed-use building's residential water meter, requiring a licensed plumber to install separate branch piping.

That a major utility built an entire municipal process around this problem is a good signal of how common and how costly the blurred-meter scenario actually is.

RUBS regulation covers the residential lease, not the commercial one

State RUBS and utility disclosure statutes are written for residential tenancies. Colorado's HB25-1090, effective January 1, 2026, is a recent example: it restricts what landlords can charge residential tenants for utilities, and it says nothing at all about commercial space or mixed-use buildings. Commercial tenants are protected by their lease's CAM and net lease terms instead, a completely separate legal framework.

Common Operational Pain Points in Mixed-Use Utility Billing

• A blended master meter makes it hard to tell how much of the bill is residential versus commercial consumption.
• Commercial tenants dispute CAM utility reconciliations that don't match their actual usage, especially high-draw tenants like restaurants or gyms.
• Residential RUBS allocations get skewed when unmetered commercial load leaks into the residential meter's readings.
• Ownership gets two disconnected reports, one for the residential side and one for commercial, instead of one consolidated view of the property.
• Compliance rules that only cover the residential lease leave the commercial side's utility terms to be handled case by case in each lease.

Apartment-Only vs. Mixed-Use: Utility Billing at a Glance

Best Practices for Mixed-Use Utility Billing

Physically separate residential and commercial metering wherever feasible

A shared master meter is the single biggest source of mixed-use billing disputes. Where separation isn't already in place, treat it as an infrastructure priority rather than a billing workaround, following the same logic behind NYC DEP's separate commercial metering program.

Reconcile CAM utility charges against actual consumption, not just square footage

Pro rata square footage is a reasonable default for maintenance costs. For utilities, it can badly misstate what a high-draw commercial tenant actually owes. Reconcile CAM utility estimates against metered consumption at least annually, the same discipline used in any billing methodology audit.

Keep RUBS allocations scoped strictly to the residential portion of the property

RUBS math should never touch commercial square footage, and commercial consumption should never enter a residential RUBS pool. Keeping the two allocation pools cleanly separated is what keeps both sides of the property compliant with their respective rules.

Track which rate class each meter is billed under

Confirm whether each meter on the property is billed at a residential or commercial utility rate, and check that the rate class matches the space it actually serves. A misclassified meter distorts recovery on whichever side is absorbing the mismatch.

Give ownership one consolidated view across both billing systems

Residential and commercial utility billing can run on different processes without producing two disconnected reports for ownership. A single consolidated view, covering both sides of the property, is what lets an asset manager actually evaluate the property's total utility performance.

What to Look for in a Utility Billing Partner for Mixed-Use Properties

• Handles RUBS or submetering for the residential side and CAM-style allocation for the commercial side, in one system
• Understands residential versus commercial utility rate classes and flags mismatches
• Reconciles shared and common-area consumption against actual usage, not just square footage
• Reports across the whole property for ownership, not two separate silos
• Manages vendor relationships across a property with mixed utility account types

How Billee Serves Mixed-Use Operators

Billee's Billing & Recovery Engine supports RUBS, submetered, and hybrid allocation models, which is the same flexibility a mixed-use property needs to run residential RUBS and commercial CAM reconciliation without forcing one methodology onto both. The platform does not assume every square foot of a portfolio is residential.

Billee's Utility Vendor Management team handles vendor relationships and invoice processing across a property's full mix of utility accounts, residential and commercial alike, so the operator isn't running two separate vendor processes under one roof. The same dedicated account manager who handles a traditional multifamily portfolio can manage a mixed-use property's utility exceptions on both sides.

For owners tracking sustainability data, Billee's ESG Reporting feeds consumption data toward ENERGY STAR Portfolio Manager, which lists Mixed Use Property as its own distinct benchmarking category, a useful starting point for owners who need to report on a property that doesn't fit neatly into one use type.

FAQ

Can you use RUBS to bill commercial tenants in a mixed-use building?

No, RUBS is a residential billing method governed by state landlord-tenant and utility disclosure statutes. Commercial tenants in a mixed-use property are billed for utilities through CAM charges or net lease pass-throughs instead, under the terms of their commercial lease.

Do commercial and residential units share a utility meter in mixed-use buildings?

They often do unless the property has taken deliberate steps to separate them, which is common enough that cities like New York run formal programs to split commercial consumption out of a shared meter. A shared meter makes it difficult to allocate utility costs accurately to either side.

How are common-area utility costs split between residential and commercial tenants?

Common-area utility costs like lobby lighting and irrigation are typically split by pro rata square footage under CAM charges for the commercial side, and folded into the standard allocation for residential common areas. The two calculations run separately even when the common area is physically shared.

Do commercial tenants pay a different utility rate than residents?

Yes. The U.S. Energy Information Administration reported a national average residential electricity rate of 16.48 cents per kWh in 2024, compared to 12.75 cents per kWh for commercial customers, so the rate class assigned to a meter matters for accurate cost recovery.

Is mixed-use utility billing regulated differently than apartments?

State RUBS and submetering statutes apply to the residential portion of a mixed-use property the same way they apply to a conventional apartment community. The commercial portion falls outside those statutes and is governed instead by the terms of the commercial lease.

Does Billee work with mixed-use properties?

Billee supports mixed-use operators through the same Billing & Recovery Engine and Utility Vendor Management products used for traditional multifamily portfolios, configured to keep residential RUBS and commercial CAM allocation properly separated on one property.

Mixed-use utility billing looks like one property but runs like two. Billee keeps the residential and commercial sides properly separated, reconciled, and reported to ownership as one picture. See what that looks like for your portfolio.

Sources

1. U.S. Energy Information Administration, "Average Price of Electricity to Ultimate Customers by End-Use Sector," 2024 data.
2. JPMorgan, "What Are Common Area Maintenance (CAM) Charges in CRE?," accessed 2026.
3. New York City Department of Environmental Protection, "Separate Commercial Meter Billing," accessed 2026.
4. Otten Johnson Robinson Neff + Ragonetti, "HB25-1090 and the Ratio Utility Billing System (RUBS)," 2025.
5. United States Environmental Protection Agency, "Property Types in Portfolio Manager," accessed 2026.