Across Europe dwellings will be constructed to comply with nearly Zero Energy Buildings (nZEB) standards by 2020. This requires highly performing dwellings, an arena previously the preserve of the Passive House (PH) Standard. This study examines the operational performance and cost of a set of nZEB dwellings built as PH dwellings and thereby investigates the potential of the PH typology as a solution to nZEB. This investigation is undertaken with particular focus on the context of social housing, given that this will account for a considerable portion (c.40%) of house-building in the next 10 years within some EU jurisdictions. Detailed construction cost comparisons are presented for an nZEB compliant PH dwelling (which is part of a scheme of 12 such dwellings) and compared to a similar dwelling which is constructed to comply with the current building regulations in the Republic of Ireland. The Indoor Environmental (IEQ) conditions, energy consumption and monitored cost of heating and ventilation are also presented. In addition, the paper presents the results of a comprehensive occupant satisfaction survey and extensive post occupancy monitoring and analysis for the scheme of PH dwellings. Finally it compares the monitored performance with that of 20 "standard" and PH dwellings, a number of which are nZEB compliant. While the study uses data across the UK and Ireland it has relevance to a much wider context for the deployment of nZEB in Europe and housing globally, and in particular the provision of social housing. (C) 2018 Elsevier B.V. All rights reserved.