In the debate on appropriate human behavior to reach sustainability and slow down climate change, there is general agreement that energy-saving heating and ventilation of buildings constitutes a main issue. Passive housing reduces energy consumption/ emissions by its high insulation of walls/windows and controlled ventilation is also used for heating via a heat recovery system. The complex new technology needs user knowledge and cooperation to be run effectively. In 2006 and 2007, bigger Passive housing estates up to high-rise level entered the Austrian market. The author led a series of partly state-supported Post-Occupancy Evaluations on seven Vienna and Salzburg projects with 550 housing units (Muehlweg, Utendorfgasse, Roschegasse, Kammelweg B and E, Dreherstrasse, Samer Moesl and Franz Ofner Strasse). Together with one internal POE of a building association, 557 units were evaluated with a questionnaire return of 345 (62%). Housing satisfaction, environmental attitudes, passive house knowledge and sympathy, heating and air quality assessment as well as “technology mediation” (i.e. help for the understanding and effective use of the heating/ventilation system) were documented. Baseline data on satisfaction with conventional housing were collected at Vienna (149) and Salzburg (88) for comparison. In five of the eight estates, passive housing produced better user satisfaction than conventional housing. 35-90% of the occupants received sufficient subjective Passive housing information, 30 to 84% expressed Passive housing sympathy compared with 67-73% in conventional housing. Estates with the highest housing satisfaction, information and sympathy reported the best “technology mediation” (48-73% “good”). Two low satisfaction estates had under 35% mediation quality. In the first occupancy period, the heating and ventilation systems were succesfully adjusted in all estates (causing major communication problems in one estate). Several findings from the POE series were useful for architects, building associations and property managements: a) Possible selection of passive house-interested tenants, communication and trouble-shooting were crucial areas for the subsequent housing satisfaction, b) tenants did neither select the passive housing mainly for its energy-saving properties nor constitute a green-oriented group, c) passive housing satisfaction did not correlate with age, gender, household size or number of children and d) a simple directions- for-use was needed for the non-familiar heating and ventilation system. In a second project in one of the two new passive housing high-rise estates, diary data were collected for 14 days from 19 apartments under winter conditions. Subjective satisfaction with room temperature and moisture was compared for 12 apartments with cheap, user-owned thermometers/hygrometers and 7 without an instrument. User thermo/hygro data were checked against Vienna University of Technology calibrated measurements in 4 apartments and found to show falsely low moisture values. Prompted by low hygrometer readings, tenants with cheap instruments were highly dissatisfied with room moisture compared to the non-instrument apartments. Consequently, calibrated thermo/hygro instruments should be given to tenants to avoid this negative prompting effect.