Adjacent to each other in the flood-prone Rockaways in NYC and completed 2 years apart, Beach Green Dunes I and Beach Green Dunes II are two of the largest multifamily Passive House projects in the U.S. Although nearly identical in appearance, they are very different under the hood. Each has a different structure, envelope, HVAC system, resiliency strategies, and operational requirements. With a focus on data, Curtis + Ginsberg and SWA will present side-by-side details of the two buildings, lessons learned, and will compare how the two buildings are operating and performing in an effort to develop best practices for highly energy efficient, multifamily design and construction.