An Experimental Study of the Effect of Energy Label Design on the Correct Evaluation of Buildings' Energy Performance and Promotion of Energy Saving

Many countries have implemented an energy labeling system that displays the energy savings performance of buildings. However, previous studies have reported mixed findings on the effectiveness of this system. This study is undertaken in Japan to assess whether energy labels are effective and validate the significance of the label design. We use an online survey to determine the effects of energy labels on target consumers. We choose two energy label designs: one with a stairs rating form design and the second with a rating scale of the energy efficiency. Adopting a within-subjects method, each respondent is shown both designs and asked to evaluate the energy-saving level based on the labels. Cross-tabulation confirms the positive effects of labeling on energy-savings levels, which are amplified by increasing the level of the reference point. The highest insulation performance level in Japan complies with a law enacted back in 1993; the results show that greater effects can be realized by increasing the level of the reference point. A logistic regression analysis shows that energy labels with the stairs rating have a negative influence, while labels with a rating scale are preferred based on ease of understanding by the respondents. This suggests that energy labels that offer a rating scale can contribute to facilitating energy savings, although there are problems with the comprehension of the gradation colors which need to be further examined. These results can act as a guideline towards optimal designs of the upcoming task of modifying the energy labeling system in Japan.