Can a real estate website that lists energy efficiency information increase traffic to energy efficient homes? This report describes a controlled study in which simulated real estate search results are used to disguise a discrete choice experiment. Using a large national sample of American home buyers (N = 1,538), we show that efficiency information can influence both simulated home purchase decision-making and willingness to pay for efficiency. We demonstrate that some strategies for presenting efficiency information are more effective than others. Specifically, voluntary labeling programs, in which only the most efficient homes receive labels, are less effective than programs where all homes are labelled. This report has important implications for cities, realtors, listing websites, and others wanting to make efficiency information more accessible.