The Dept. of Energy is responsible for national weatherization oversight and funds much of the assistance for weatherization provided to low-income households in the United States. The DOE sponsors a Weatherization Assistance Program Technical Assistance Center (WAPTAC) to support and provide guidance to states and sub-grantees (the local agencies that deliver actual weatherization services in each state). Many of the links listed below come either from DOE web sites or from the WAPTAC web site. All of the following links lead to web pages that either deal directly with weatherization practice or policy, or they lead to information about related topics in energy efficiency.