The recent Supreme Court decision limits the immediate ability for the federal government to regulate greenhouse gas emissions. There are other tools available, but Carlos Martín with the Harvard Joint Center for Housing Studies believes the critically important efforts to reduce greenhouse gas emissions from existing homes will fail unless they are done in ways that consider the nature and structure of the highly fragmented remodeling industry, and the diversity of household needs. With 20 percent of U.S. greenhouse gas emissions directly attributed to housing—the equivalent of the sixth largest global emitter—most of the existing housing stock needs massive transformation to become more energy-efficient. Current energy retrofits are known to reduce individual home energy use by 30 to 70 percent. Transforming residential energy use to net-zero carbon through a combination of property-level renewables, electrification and energy-efficient retrofits is aspirational, but increasingly attainable.