A demographic shift is underway in Australia; the number of people aged 65 and over is rapidly increasing. Regulations have been implemented to enhance the quality of care being provided in nursing homes; however, in the aged care sector there is little by way of guidance addressing design and performance issues in regards to Indoor Environmental Quality (IEQ), and there is still uncertainty as to the perceptions of residents on specific IEQ factors. The objectives of this study are to determine: how accredited facilities are performing in regards to thermal comfort conditions; how indoor environmental factors can be assessed in a non-intrusive way; and how occupants perceive their thermal environment. Air temperature and relative humidity were monitored over ten months in six nursing homes located in southeast NSW using 305 loggers. Subjective perception of the thermal environment was gathered from 157 residents, 31 family members and 64 staff who completed a questionnaire at the same time that local environmental parameters were monitored. Results show how accredited nursing homes performed in regards to thermal comfort, along with a detailed description of the non-intrusive methodology adopted to assess IEQ factors. Subjective responses of occupants, along with adaptive behaviour strategies employed by participants to counter unsatisfactory thermal conditions, were also examined. This study has practical implications for the aged care sector and provides quantitative evidence on how nursing homes should be designed and operated to enhance satisfaction and well-being of occupants.