The "Build Now Act of 2025" proposes significant adjustments to the allocation of Community Development Block Grant (CDBG) funds. Its primary goal is to incentivize and reward localities that demonstrate progress in increasing their housing supply. These adjustments are based on a newly defined metric called the housing growth improvement rate , which compares a recipient's recent housing unit growth to its prior growth. Under this bill, eligible recipients, defined as metropolitan cities or urban counties receiving CDBG funds (with certain exceptions for areas with low housing costs, high vacancy rates, recent disasters, or lack of zoning authority), will see their allocations modified. Localities with a housing growth improvement rate at or above the median for all eligible recipients, or those classified as "extremely high-growth recipients" (achieving an annual housing growth rate of 4% or more), will receive a bonus amount . This bonus is funded by reductions from other recipients. Conversely, eligible recipients whose housing growth improvement rate falls below the median will face a 10 percent decrease in their CDBG allocation. The Secretary of Housing and Urban Development is responsible for calculating these rates using Census Bureau data and must publish an annual report detailing each recipient's performance and allocation changes. The Act also mandates that the Secretary provide guidance on best practices to reduce regulatory barriers and increase housing supply, with these provisions taking effect in the second full fiscal year after enactment and continuing through fiscal year 2042.