national multiple family submetering and allocation billing program ...

A slight variation on hybrids is hot water/point-of-use submetering. This is a system
where there is a single hot water entry line that is submetered, and selected cold water end uses
are measured using point-of-use meters (as described above). Often, a point-of-use meter is only
installed on each of the toilets, and the rest of the cold water is allocated by one of the methods
described above.
Hot water hybrids are often mistakenly labeled as “submetered”. However, it is really
only partial-capture submetering, since only a portion of the water usage is physically measured.
Therefore, they were considered a distinct type of billing in this study.
Ratio Utility Billing Systems
Ratio utility billing systems (RUBS) use an allocation formula to estimate water
consumption for each unit in a multi-family dwelling. RUBS systems are not based on the actual
consumption at each unit, rather individual bills are prorated from the overall utility master meter
bill. Typically, the monthly (or bi-monthly) water bill will be allocated between occupied units
based on one or a combination of quantitative measures. The allocation formula can be based on
a dwelling unit’s area (square footage), number of bedrooms, number of occupants, number of
bathrooms, or number of fixtures. Often, but not always, a portion of the total master meter bill
is still paid by the owner, to account for common area usage, irrigation, administrative offices,
etc.
RUBS example #1, occupancy – After a property subtracts 25% for common area use,
the remaining water bill is $3,000 for combined water and wastewater. If the entire complex has
300 residents, and Unit A has 4 residents, then Unit A’s prorated portion of the bill is:
4
*$3000
300
= $40 . Thus, Unit A would receive a bill with an estimated consumption charge of
$40.
RUBS example #2, square footage – After a property subtracts 25% for common area
use, the remaining water bill is $3,000 for combined water and wastewater. If the entire complex
has a total square footage of 50,000 sf, and Unit A is 1,000 sf, then Unit A’s prorated portion of
1,000
the bill is: *$3000 = $ 60 .
50,000
A variation on RUBS occurs when each unit is billed with a flat monthly fee that is based
on one of the aforementioned quantitative measures. For example, a property may send a bill to
8