Weatherization Assistance Program Improvements Act of 2023 This bill expands the Weatherization Assistance Program of the Department of Energy (DOE). The existing program reduces energy costs for low-income households by increasing the energy efficiency of their homes. The bill establishes a Weatherization Readiness Fund from which DOE may distribute funds to states for repairing structural defects or hazards of such homes so that weatherization measures may be installed. In addition, the bill increases the cap on the amount of funding that may be spent on (1) each home for labor, weatherization materials, and related matter; and (2) renewable energy systems in homes. The bill also eliminates a prohibition on providing funding for partially weatherized homes that have received assistance within the past 15 years. Instead, the bill applies this prohibition on fully weatherized homes.