PurposeRetrofitting single glazing with double glazing saves energy and enhances indoor comfort, however replacement can be expensive. Secondary glazing is an easier-to-install, cost-effective retrofit alternative. There is a gap in the literature about post-retrofit occupant satisfaction with secondary glazed windows in Australia.Design/methodology/approachThis research addresses this gap, with an online survey completed by 56 respondents in New South Wales and the Australian Capital Territory who retrofitted secondary glazing. This research seeks a deeper understanding of occupier views. Issues of validity and internal and external reliability were addressed in the research.FindingsStrong satisfaction and significant improvement in indoor comfort was found. Over 80% of respondents felt their home had better thermal and noise insulation. Nearly 79% found a positive impact on their property value and 77% would retrofit secondary glazing if they moved. Occupants considered secondary glazing a suitable technical, economic and environmental alternative to double glazing in retrofits.Research limitations/implicationsThere is a chance of sampling bias; only satisfied respondents answer the survey. Survey data was collected from occupants located in a small geographic area and who used the same manufacturer. Different climatic conditions, varying specifications and quality of installed systems could influence perceptions.Practical implicationsMany reported health and wellbeing improvements, higher comfort, higher property value and willingness to invest in residential energy efficiency measures. These findings need to be more widely known in the Australian market.Originality/valueFew studies focus on retrofitting secondary glazing to Australian residential buildings. This study highlights the social, economic and environmental benefits perceived by occupants post-retrofit.