This report updates ACEEE's 2013 assessment of multifamily energy efficiency programs in US metropolitan areas with the most multifamily households. Using housing, policy, and utility-sector data from 2014 and 2015, this report documents how these programs have changed in the context of dynamic housing markets and statewide policy environments. The report also offers an analysis of the number, spending, offerings, and targeted participants of current programs and their potential for further expansion.

Through field-testing and analysis, this project evaluated whole-building approaches and estimated the relative contributions of select technologies toward reducing energy use related to space conditioning in new manufactured homes. Three lab houses of varying designs were built and tested side-by-side under controlled conditions in Russellville, Alabama. The tests provided a valuable indicator of how changes in the construction of manufactured homes can contribute to significant reductions in energy use.

Energy burden is the percentage of household income spent on home energy bills. In this report, ACEEE, along with the Energy Efficiency for All coalition, measures the energy burden of households in 48 of the largest American cities. The report finds that low-income, African-American, Latino, low-income multifamily, and renter households all spend a greater proportion of their income on utilities than the average family. The report also identifies energy efficiency as an underutilized strategy that can help reduce high energy burdens by as much as 30%. Given this potential, the report goes on to describe policies and programs to ramp up energy efficiency investments in low-income and underserved communities.

Residential air-source heat pumps (ASHP) are a heating and air-conditioning technology that use electricity to provide a combination of space heating and cooling to homes. A new generation of ASHPs has come to market over the past five years. This report evaluates the key market barriers as well as potential opportunities to leverage. Based on an assessment of the regional ASHP market, it is clear that while ASHPs have established a viable and growing market, there remains a significant opportunity to further accelerate adoption of the technology and in the process achieve energy and cost savings to the Northeast and Mid-Atlantic region.

Energy efficiency collaboratives vary greatly and are typically designed for a specific jurisdiction, making them hard to compare side by side. This guide seeks to highlight a few common elements and draw conclusions on the overall effectiveness of specific characteristics of collaboratives. This guide defines and examines four different types of collaboratives in terms of their origin, scope, decision-making method, membership, duration, available resources, and how they interact with and influence their respective commissions.

This report identifies and discusses factors that should be considered in evaluating model choices for administering and implementing ratepayer funded energy efficiency programs.

This report considers consumers' perspectives on policy and regulatory issues associated with the administration of energy efficiency investments funded by ratepayers of electric and natural gas utilities.