President George W. Bush as signed an energy bill that will boost fuel-economy requirements for cars and light trucks to 35 miles per gallon (56 km per L) by 2020—the first such increase since 1975. The bill also mandates using 36 billion gallons (136 billion L) of biofuels by 2022 and increasing efficiency requirements for some appliances and light bulbs. For example, all light bulbs must use 25 to 30 percent less energy than they do today by 2014; this will save consumers more than $40 billion in energy costs. The bill also requires that the Washington, D.C.-based agencies, U.S. Department of Housing and Urban Development and, U.S. Department of Agriculture meet energy-efficiency requirements. Under existing law, HUD and USDA are required to write energy-efficient standards for public and assisted housing and housing with federally insured mortgages. Currently, such standards have to be at least as stringent as ANSI/ASHRAE/IESNA Standard 90.1-1989, “Energy Standard for Existing Buildings Except Low-Rise Residential Buildings,” and Council of American Building Officials-1992, Accessible and Usable Buildings and Facilities. When 90.1 or CABO is updated, the agencies have one year to review their standards but that rarely has taken place. Under the new law, HUD and USDA will be required to implement standards at least as stringent as Standard 90.1-2004 for all new construction and rehabilitation of public and assisted housing and housing with federally insured mortgages.