Habitat for Humanity of Michigan (HFHM) seeks to improve energy efficiency and promote reduced energy consumption among Habitat homes through improved building science and education. To this end, our team conducted a thorough analysis of building practices, environmental attitudes, and energy consumption utilizing interviews of Michigan Habitat affiliates, surveys of Habitat partner families, and analysis of actual home energy consumption data. Our goals were to create a scalable resource-reduction plan for HFHM based on expected versus actual energy consumption in homes, develop recommendations to motivate reduced energy consumption among families, and identify and communicate best practices within affiliate organizations. Additionally, we worked with HFHM to identify areas for future research and opportunities to partner with UM SNRE on prospective Master's Projects that could help HFHM meet their long-term sustainability goals.

Using this three-pronged approach, we first used interviews to identify home construction and partner family communication best practices among 21 Michigan affiliates. We also worked with these affiliates to determine challenge areas such as funding and partner family education.

We developed a partner family survey through which we gathered information on approximately 120 partner families' demographics, attitudes on energy and the environment, energy consumption behavior, and experience in their home. We supplemented these surveys with actual electricity and natural gas consumption data from utilities. Using these data, we created regression models to find associations between household characteristics, attitudes, reported energy usage behaviors, and actual energy consumption. Finally, we compared energy consumption in these Habitat homes with similar non-Habitat homes from the US EIA's Residential Energy Consumption Survey.

In general, Habitat homeowners correctly assessed the relative energy efficiency of their homes. Respondents who perceived their homes as being more energy efficient consumed less energy, on average, than those who perceived their homes as being less efficient. When comparing energy consumption between Habitat homes and similar non-Habitat homes, Habitat homes consumed less over the course of a year than non-Habitat homes when controlling for factors such as home size, number of household members, and climate.

Our models indicated several significant drivers of household energy use and potential areas for intervention in building characteristics and homeowner preparation. These include nighttime thermostat settings, installing smart power strips to automatically turn off TVs and gaming systems when not in use, and quantifying monetary losses associated with the use of secondary freezers and electric space heaters, as well as continuing the policy of avoiding central air conditioning. However, we found little relationship between attitudinal variables, such as the extent to which self-reported environmental concerns motivate behavior, and energy consumption.

We also suggest that HFHM work with future UM SNRE teams to develop additional educational materials for partner families, such as a Home Ownership Manual, and create a scalable plan to expand energy conservation best practices to affiliates across the country. We expect our project and future UM SNRE master's projects to improve the lives of HFHM families through decreased energy costs, improved home comfort, and greater sense of engagement with their environment and community.