Low-income housing plays an important, but frequently overlooked, role in energy use reduction. Barriers persist for low-income households to participate in energy efficiency programs and adopt efficient lifestyles. However, there has been only limited research into energy efficiency barriers faced by low-income households. Existing energy research studies primarily focus on homeowners whose demographic and socio-economic profiles are likely to be very different from low-income households or renters—limiting the applicability of previous findings to low-income households. This study aims to identify and evaluate the importance of the energy efficiency barriers faced by low-income households. A questionnaire survey was conducted with 212 low-income households in Australia. After randomly dividing the data into calibration and validation samples, an explor-atory factor analysis (EFA) of the calibration sample identifies four energy efficiency barrier factors of financial, decision-making, information, and split incentives. These four factors are then vali-dated by confirmatory factor analysis (CFA) of the validation sample in terms of goodness-of-fit, reliability, and validity to confirm financial as the most highly rated energy efficiency barrier. This research contributes to bridging the knowledge gap of the energy efficiency barriers of low-income households and providing a validated CFA model as a tool for assessment. The results provide a better understanding of the barriers involved and research evidence to facilitate the formulation of policies to overcome them.