Abstract: An online energy audit system poses and collects responses to a list of survey questions regarding a subject house from a remote occupant via a survey UI. Survey responses are stored in an energy-use profile associated with the subject house and are used to populate model inputs to an energy-use software model, from which an energy-efficiency score is derived. To help a remote occupant choose appropriate answers and to facilitate completion of the survey, the survey UI includes question-specific house-feature images associated with some or all questions. Survey questions are designed to be easy for a homeowner to understand, and the survey is kept short. The energy-efficiency score of the subject house is presented to the remote occupant in comparison with comparison energy-use data together with an action message to encourage the remote occupant to improve the energy score of the subject house.