“RUBS” and “submetering” are the two ways multi-unit properties turn one master utility bill into many resident bills. In most of the rental world, choosing between them is a business decision. In California manufactured housing, it is substantially a legal one — and since 2022, the law has moved decisively toward measured, bill-derived charges. This guide explains both methods, then walks through what California's Mobilehome Residency Law and Public Utilities Code actually permit.
What Is RUBS?
RUBS — Ratio Utility Billing System — divides a property's master utility bill among residents by formula instead of by meter. Common formulas allocate by square footage, by number of occupants, or as a fixed equal share per unit. Nothing is measured at the individual space; each resident pays a calculated fraction of the property's total.
RUBS exists because retrofitting meters costs money and some utility configurations make individual metering hard. Its weakness is inherent: a resident's bill has no relationship to what that resident actually used. A single space with a leak, a pool fill, or heavy usage is subsidized by every other space on the formula.
What Is Submetering?
Submetering puts a meter on each space behind the property's master meter. The serving utility bills the property on the master meter; the operator (or a billing provider) reads each submeter and bills each resident for measured consumption. Every charge traces to an opening read, a closing read, and a rate.
Most California manufactured housing communities built with master-metered utilities were built with submeters — the configuration the Mobilehome Residency Law's billing rules are written around.
The Comparison
| RUBS | Submetering | |
|---|---|---|
| Basis of each bill | Formula share of the master bill | Measured consumption at the space |
| Fairness | High users subsidized by low users | Each resident pays for their own usage |
| Conservation incentive | None — usage doesn't change the bill | Direct — usage is the bill |
| Dispute defensibility | Depends entirely on the formula's documentation | Meter reads on the bill; independently verifiable |
| California MH water/sewer | No statutory safe harbor (see below) | The method the statute is written around |
What California Law Says for Manufactured Housing
Two bodies of law govern here, and they are stricter than the rules for apartments.
Water and sewer: the property's actual bill is the only lawful basis
Since AB 1061 (Cal. Civ. Code § 798.40(c), operative January 1, 2022) — extended to every water purveyor, including municipal and district providers, by AB 604 (operative January 1, 2024) — management “shall only bill” submetered water service using the statute's bill-derived methods. § 798.40(c)(1) authorizes usage-based methods keyed to actual submeter readings. Occupancy-based, square-footage, and fixed-ratio (RUBS-style) allocation have no statutory safe harbor for water and sewer in this setting. The administrative fee is capped by § 798.40(c)(3), and the sum of all residents' charges can never exceed the purveyor's bill itself.
Gas and electric: direct-service rate parity
Cal. Pub. Util. Code § 739.5(a) requires a master-meter customer to charge each user “at the same rate that would be applicable if the user were receiving gas or electricity directly” from the serving utility. Billing a resident as if served directly requires knowing what that resident consumed — which is what a submeter does. A formula share of the master bill does not produce a rate-parity bill, and the total billed can never exceed the master bill.
For the complete rule set — meter readings on the bill, CARE/FERA passthrough, itemization, disclosures, and the rest — see the 14 California rules.
The Decision, Honestly Framed
For a California manufactured housing community, this is not really a RUBS-vs-submetering choice the way it is for an apartment operator in another state:
- If your spaces are submetered — bill from the meters. It is the compliant path, the fairer path, and the defensible one in a dispute.
- If some utilities are master-metered without submeters — the lawful options are narrower than the general-rental playbook suggests, especially for water. Divided charges must trace to the property's actual bill, common-area usage must be accounted for, and the total can never exceed the master bill. Get the specific configuration reviewed before choosing a method.
- If a billing provider is proposing RUBS for water in a California manufactured housing community — ask them to walk you through § 798.40(c) first.
Frequently Asked Questions
Does RUBS save money over submetering?
RUBS avoids meter installation and reading costs — that is its whole appeal. But in California manufactured housing, avoided hardware cost does not change what the statute permits for water and sewer, and a billing method that cannot survive a resident dispute is not cheap.
Our community has always billed this way. Doesn't that count?
The water rules changed on January 1, 2022, and again on January 1, 2024. Practices that were lawful before those dates are not grandfathered. Bills issued under the old method after the operative dates are the operator's exposure, not the method's defense.
What about trash or other flat services?
Flat pass-through services like trash are different from RUBS: the charge is not a formula share of a metered utility but a documented amount actually assessed for the service. Cal. Civ. Code § 798.41 requires it to be separately stated and limited to what is actually charged. See rule 13 in the 14 rules guide.