As we designed and built the first large multifamily Passive Houses, we selected systems without available best practices for creating highly efficient buildings of this scale and density. Most of the buildings to be discussed have been in operation for at least one year. We will review lessons learned and initial data showing how these buildings (utilizing a range of systems) are working and will provide valuable information to attendees seeking to construct similar types of buildings. In addition to monthly utility data and whole building EUIs, the team will present an analysis of 15 minute data from a select few NYC projects in an attempt to better isolate energy use associated with particular end uses