ABSTRACTThis paper reports the findings of a case study conducted to learn about the information, actors, actions, and processes involved in energy-efficiency investment decisions in the social-housing sector. These decisions draw on environmental, social, and economic factors, which are studied from a “triple bottom line” (TBL) accounting perspective. The quantitative methods we use rely on Levels I, II, and III fair-value measures similar to those used in financial accounting. The qualitative methods rely primarily on interviews conducted and transcribed by the researchers. Our main findings show that a pure financial bottom-line approach would not fully indicate the overall desirability of the type of energy-efficiency investment undertaken in this case. By factoring in other quantitative and qualitative outcomes drawn from the research methods applied, a different conclusion may be reached.Data Availability: Available upon request from the authors.