national multiple family submetering and allocation billing program ...

Table 5.32 Comparison of sample size from multi-family billing program studies
Study
No. Properties Included in Analysis
Description of Analysis
In-Rent Sub. RUBS HWH
National
Postcard Survey 6493 273 595 41
Submetering and Manager Survey 858 118 177 22
Allocation Billing Statistical Model #1 705 101 150 -
Program Study Statistical Model #2 703 100 150 -
(2004)
Statistical Model #3 531 79 136 -
Matched Pair 29 21* 14 -
Pre-Post Conversion - 6 39 1
Wilcut (2002) Paired Comparison 5 5 5 -
Strub (2000) Pre-Post Conversion - - - 2
Koplow and Lownie Paired Comparison 14 9 9 -
(1999)
Dietemann (1999) Paired Comparison 5 1 - -
Pre-Post Conversion - 9 - -
* 7 HWHs were grouped with the submetered for this analysis.
Table 5.33 shows a comparison of the water savings found in this study with previous
research efforts (please refer to Chapter 2 for more details on these studies). In general, the 15%
savings from submetering found in this study is lower than most of previous findings. An
insufficient sample size precluded the inclusion of water savings conclusions for hot water
hybrid properties. This study did not find statistically significant water savings from RUBS.
The Wilcut (2002) study found moderate savings of 3% for RUBS properties, while the Koplow
and Lownie (1999) found more substantial savings of 6% to 27%.
Since its publication in 1999, the water savings results from submetering and RUBS
published in the Koplow and Lownie study have been frequently cited, particularly by the billing
service industry. The differences in the findings between the Koplow and Lownie study and this
study should be looked at more closely.
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