national multiple family submetering and allocation billing program ...

EXECUTIVE SUMMARY
More and more buildings in the multi-family housing sector are converting to systems
where each multi-family dwelling unit pays for water and wastewater directly instead of
including these charges as part of the rent. The three most common ways in which separate
billing is accomplished are: (1) Through direct submetering of water use by means of a water
meter installed on a single or multiple points of entry water line(s); (2) Through a Ratio Utility
Billing System (RUBS), which bases the water bill on an allocation formula that uses floor
space, number of occupants, etc.; or (3) A hybrid of the two where total water use is estimated
based on the ratio of metered hot (or cold) water use (and sometimes selected appliances) in a
unit to the total water use of all occupants. It is estimated that there are now more than 1.2
million apartment renter households that are billed separately for water and sewer using one of
these billing system methods (NMHC 2001). 1
RESEARCH OBJECTIVES
The goals of the National Multiple Family Submetering and Allocation Billing Program
Study were to determine the merits of separate billing programs including the potential water
savings, costs and benefits from various perspectives, and the accompanying administrative and
regulatory issues. In the study, a retrospective analysis of water use in multi-family properties in
13 cities was conducted. The 13 study cities were weighted towards the West and southwestern
region of the United States, but contain a wide variety of utilities serving a broad and diverse
group of customers. Properties equipped with submeters or that have undergone a billing system
conversion (impacted properties) were identified and compared against control (in-rent)
properties where water and wastewater fees are included as part of the rent. The study compared
the two groups using historic billing data provided by participating water utilities combined with
an extensive series of mail surveys and site visits. The data collected for study provides a wealth
of information about how submetering and allocation affect water use, property owners, and
residents. Embedded in these data are insights into this developing industry, including the
1
Based on data from the 2001 American Housing Survey. Assumes a multi-family property has at least five
dwelling units. The number is higher if smaller properties are included in the analysis.
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