The Northwest Energy Efficiency Alliance (the Alliance), as a regional utility consortium, commissioned this study to establish the current practices and attitudes that characterize the energy efficiency of new multi-family residential construction as the basis for developing and evaluating regional market transformation programs targeting this sector. This sector differs from other building sectors in that no previous baseline has been collected. In the late 1980s, the single- and multi-family sectors began to diverge in characteristics, particularly along the lines of heating system selection, so that the multifamily sector could no longer be described by studies of the single-family sector.