Individual Meters vs Master Meters
Utility companies distribute electric, natural gas, and water to residential locations and measure the amount consumed based on metering devices (also see OPC Guide to Smart Meters).
Direct meters measure the amount of electric, natural gas, and water to an individual residential location (single home, apartments, condominiums, mobile home, etc.). Consumers in these dwellings must have an account with the utility distribution company in their name. The utility reads the meters, calculates the amount used and sends a bill to the individual responsible for payment This allows the consumer to monitor consumption, reduce consumption if necessary, and contact the utility to address unusual increases or decreases in consumption (meter malfunction or other issues).
Master meters involves certain locations with multiple apartments, condominiums, mobile home parks. A master meter is a single meter used to measure the total amount of electric, natural gas and water consumed. Where master meters exist the owner/manager of the property receives one total bill for each billing period. The owner/property manager may pass the utility costs to the building occupants, as individual residents do not know the exact amount of electric, natural gas, or water consumed in each dwelling. Based on a survey commissioned by the Maryland Public Service Commission, in 2018 there were 840 electric master meter accounts and 3,393 natural gas accounts identified. The master meter owner/manager typically calculates the amount to charge each dwelling in one of three ways, often referred to as R.U.B.S. (Ratio Utility Billing System):
The yearly charges are rolled into the individual lease/condominium fee amount. This requires the owner/manager to forecast utility costs for the life of the lease, or make specific periodic assessments to cover utility costs. Renters/owners are not able to analyze or plan for such increases.
The owner/manager takes the total utility charge and divides the cost evenly to each dwelling unit. Thus, all occupants pay the same regardless of consumption.
The owner/manager takes the total utility charge and calculates the cost depending on the square footage of individual dwelling unit. The individual occupant’s consumption has no relationship to billing charged.
Utility assistance and programs to reduce utility consumption are not typically available to master metered buildings since they are not individual billed customers. Individual residents do not know how much utility service they use, thus there is no incentive to reduce waste or take advantage of efficiency measures.
Sub-meters locations are multiple dwelling units constructed since 1978, or multiple dwelling units that have retro-fitted master meters. Maryland in 1978 passed a law, which was codified in 2010 to Public Utility Law §7-304, which exempted building constructed before 1978 from requirements to retrofit building to individual meters. In these situations the multiple dwelling unit has a master meter, after the master meter sub-meters are installed. Sub-meters provide a separate meter for each unit, building owners/managers read these individual meters and provide bills to individual owners. A separate sub-meter accounts for the utility costs for public areas (heating, elevators, offices, etc.); these costs are then made part of the rental agreement or periodic assessments. Residents in sub-metered dwellings are eligible for electric and natural gas assistance through Maryland Department of Human Services, Office of Home Energy Programs.