In a multifamily housing complex with 300 units that are individually sub-metered, what is the minimum number of units to review during a pre-audit utility bill analysis?

In a multifamily housing complex with a significant number of units, such as 300, it is often impractical and unnecessary to review every single unit during a pre-audit utility bill analysis. Instead, selecting a representative sample allows analysts to accurately assess utility usage patterns and anomalies across the entire complex without incurring excessive time or resource costs.

By focusing on a representative sample, the analysis can reflect the various living situations and potential discrepancies within the building. This method can help identify trends, average consumption, and any issues with billing or metering without the need to delve into each unit's data individually.

The other approaches would not be as effective for a variety of reasons. Reviewing 50% of the total units could still lead to redundancy or misses in capturing the full spectrum of usage behavior. Examining only the lowest billing units would ignore those with higher usage that could reveal significant issues or concerns. Lastly, reviewing all 300 units is typically excessive and inefficient for an initial analysis, as trends can be gleaned from a well-chosen sample. Thus, the strategy of using a representative sample is both practical and effective for utility analysis in multifamily settings.