The purpose of this research is to identify constraining variables that may impinge on adopting energy-efficient practices, materials, equipment and technology in households. The intent is to uncover relationships of attitudes, beliefs, knowledge and other resource constraints to: (1) existing housing adaptations and adjustments for energy efficiency; and (2) more efficient use of energy in homes. A second objective is to identify existing practices used to reduce energy use and the adaptations made to the existing structure, materials, equipment and technology for energy efficiency as well as their intentions to make future adaptations. Constraint variables include knowledge of existing energy-efficient practices and technology; economic constraints (household income, cost as a problem, financial need and existing energy costs); obstacles to making changes (lack of information, assistance, time, cooperation, trained persons and the condition of home); and demographic variables (age, education level and urban/rural). Attitude and belief constraints include measures of felt responsibility for energy use-related actions that impact the natural resources and environment, and measures of concern. These constraints may impinge on or contribute to making energy-efficient changes in residential households. Questionnaires were mailed to a random stratified sample of 800 households in Nebraska (US state) in April and May of 2008, resulting in a 29% return rate. The analysis indicates that the research produced information about constraining factors that impact the existing energy-efficiency levels of households. The use of energy-efficient equipment and technology, and behaviour practices that reduce energy use are related to those barriers. However, residential energy use and behaviour change result from a range of psychological and contextual influences on behaviour. Behaviour is often inconsistent with attitudes because of the presence of various constraining factors that preclude consistency with behaviour. Educational programmes have a challenging task if they are to alter attitudes and norms to overcome situational constraints. It may be more fruitful to educate and to remove the constraints impinging on those who already have a positive attitude about the need to increase energy efficiency for whatever reason.