Nearly two dozen efficiency programs are helping builders and designers construct growing numbers of new homes and buildings that can produce at least as much energy as they consume or be modified to do so in the future.
If the United States is to dramatically reduce greenhouse gas emissions, we need new homes and buildings to minimize energy use and emissions. A new ACEEE white paper identifies 22 programs advancing zero-energy, zero-carbon, or zero-energy-ready buildings, including 14 residential and 8 commercial programs.
What is a zero-energy building? What is a zero-carbon building?
A zero-energy building generates at least as much energy as it consumes over a year, often using solar panels. Some aim for net-zero-carbon or -emissions, meaning they emit net zero carbon dioxide annually. The difference between zero-energy and zero-carbon classification is that the latter accounts for the carbon emissions associated with electric power generation, which vary based on when the power is needed and which generating plants are operating at those times.
Short of building to zero-energy or zero-carbon criteria, many programs promote zero-energy-ready buildings, which are efficient enough that they could be operated with onsite energy and be zero energy if a solar energy system were eventually installed. Zero-energy-ready buildings often include floor and roof configurations, conduit or wiring, and electric panel capacity that will make it easy to hook up electric heating and cooking equipment and solar panels in the future. Zero-energy and zero-energy-ready buildings typically use 25–50% less energy than current building code requirements.
Programs have growing budgets and participation
The 22 programs we profile have a combined annual budget of approximately $110 million for 2024. This is about 70% more than the total budget for similar programs examined in a 2020 ACEEE study.
Across these programs, more than 5,000 new single-family homes, nearly 25,000 new apartments, and 222 new commercial buildings totaling 9.5 million sq. ft. have been completed. These figures do not include most of the 21,000 homes completed under the DOE Zero-Energy-Ready Homes program, a growing national program.
Most of the completed homes and apartments are in Massachusetts and New York, while a substantial majority of completed commercial buildings are in Oregon, New York, and Vermont. Many other projects are currently under construction, including more than 60,000 apartments and 325 commercial buildings (totaling more than 94 million sq. ft.). California accounts for a large share of these pending projects. Several programs explicitly target affordable housing, while others offer higher incentives for affordable housing.
Electric space and water heating are becoming more common in these programs
Compared to our 2020 study, we find that a growing number of new construction programs require electric space and water heating. Some other programs allow fossil-fuel space and water heating but provide extra incentives for electrifying these end uses. Several program managers note that going all-electric can become a path to zero emissions as their electric grids become increasingly clean.
Key lessons are emerging
We contacted each of the program administrators for an interview to learn more about their programs and the lessons learned. Several themes emerged:
- Residential programs find it important to train builders on how and why to build zero-energy/carbon buildings and make special efforts to target the largest builders, who can have the greatest impact.
- Commercial programs find that building a community of practitioners is very important, as is intervening early in the design process and using this early intervention to set and follow through on energy design goals.
- Both residential and commercial programs find that it is essential to highlight the multiple benefits of zero-energy homes and buildings. These benefits include impacts on comfort, health, building resilience, employee satisfaction, and operating cost savings. Programs also report that it is helpful to have simple incentive structures that builders, designers, and developers can easily understand.
Minimizing new buildings' energy use and emissions is essential for combating climate change and can improve occupant comfort and health. Programs to advance zero-energy and zero-carbon buildings can be an important contributor to efforts to transform new construction markets and ultimately make designing and constructing these buildings common practice.
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