The bipartisan 21st Century Road to Housing Act became law early Saturday after President Donald Trump declined to sign, allowing the bill to pass automatically under the Constitution. The legislation contains 47 proposals aimed at expanding supply and cutting costs amid high mortgage rates and record home prices.

Key measures target manufactured housing, office‑to‑apartment conversions, and a pilot for grants and forgivable loans to repair older homes. The law also caps investor ownership at 350 single‑family homes, preventing further bulk purchases by firms like Blackstone but not forcing current owners to sell.

Local zoning remains the main bottleneck. The bill encourages municipalities to adopt more development‑friendly land‑use rules, a change that could unlock 2.5 million housing units over the next decade, according to a 2025 Goldman Sachs report. Execution hinges on HUD’s staffing, which has been cut since the Trump era, and on local political will.

For developers, the law offers new pathways to build and finance projects, potentially easing supply constraints and moderating price growth. Investors face a new ceiling on large‑scale acquisitions, which may shift capital toward smaller‑owner portfolios. Market participants must monitor HUD’s rollout and state‑level zoning reforms, as the law’s effectiveness will shape the housing market’s trajectory for years.