Ratio Utility Billing (RUBS): Formula, Records, and Local Rules

Ratio utility billing, or RUBS, allocates a master-metered property’s utility bill across units by a stated formula instead of measuring each unit’s actual consumption. An owner may consider it for water, sewer or other shared costs, but a formula is only one part of the decision. The lease, utility bill, building setup and local rules determine what can be charged at a particular property.

What a RUBS formula actually does

A formula might use unit size, bedrooms, occupants or a combination. Those are allocation factors, not meter readings. The choice changes who bears more of a shared bill. Separate any common-area usage and fixed charges before modeling the resident amount, and show the same inputs on the bill that you use in the calculation. When comparing billing periods, record utility-rate changes, seasonal use and occupancy changes so a higher invoice is not automatically attributed to resident behavior.

Illustration, not a bill to send: Suppose a $1,200 master bill contains $200 that the owner will not allocate and $1,000 under review. Four units have weights 1, 1, 2 and 2. Six total shares would produce $166.67, $166.67, $333.33 and $333.33 after rounding to the cent. Whether any of those charges is lawful depends on the property’s lease, local rule and charge category. The math alone cannot answer that question.

Before selecting a provider or changing a lease

• Map the service: identify the utility, master meter, common-area use, existing individual meters and the billed period.
• Read the lease and local rule: confirm what the resident or commercial tenant agreed to pay, when a change can take effect and what disclosure is required. Commercial and residential terms differ.
• Test the provider’s output: request a sample bill showing source invoice, factors, occupied units, credits, administrative charges and a dispute path.
• Assign the correction owner: decide who reconciles the utility invoice, approves a formula change, answers a billing question and reverses an error.

California Civil Code section 1954.201 states the Legislature’s purpose for a chapter on submetered water service, and section 1954.205 sets charges for that submetered-water regime. A ratio allocation without individual submeter readings is different. Those sections do not, by themselves, authorize a RUBS charge at every California property or establish a universal RUBS fee.

Where local rules can change the answer

The Los Angeles Housing Department’s December 2025 report described RUBS for master-metered rentals and recommended restrictions and disclosures for a proposed ordinance. A recommendation is not an enacted rule. As of October 3, 2026, the City Clerk’s Council File 22-0178 is pending in Housing Committee after an August 28 rereferral; its last listed legislative action did not enact the December 2025 recommendation. Check the file again, the property’s rent-control status and the existing lease before treating a charge or notice as permitted.

Conservation and fairness need separate evidence

A resident paying a formula share may have a reason to watch total utility costs, but that does not prove lower consumption. A conscientious resident can still pay for another unit’s use. Submetering records actual unit use but requires equipment, reading and billing controls. Compare installation cost, invoice accuracy, water leaks, common-area usage and resident questions before choosing either approach.

For an existing program, keep the utility invoice, allocation inputs, dated lease disclosure, each issued bill and corrections together. That gives the owner and resident a way to reconstruct a charge. If those pieces cannot be reconciled, fix the data or billing method before drawing conclusions about savings.