The Northwest Energy Efficiency Alliance is currently funding the Distribution Efficiency Initiative (DEI) Project. One major component of the DEI is to perform site visits for a sample of 500 representative single-family homes in the Pacific Northwest. DEI will provide the Alliance with a baseline of Pacific Northwest residential building stock characteristics for single family homes. One residential sub-sector that is not represented in this effort is multifamily dwellings. This multifamily building stock study served to collect information on the multifamily residences and common areas for a sample of complexes in the Pacific Northwest. Of the almost 5,000,000 dwelling units in the PNW, 24% are multi-unit dwellings with 17% of the total in larger (≥5 units) multifamily buildings. RLW concentrated their efforts on the larger multifamily units, targeting two complex sizes: complexes with 5 to 19 units, and complexes with greater than 20 units. The table below shows that there is an approximately equal distribution of complexes in each of the size categories in both the population and the sample.