Putting one home on every currently listed lot of 5 acres or less would cut that shortage to roughly 4.44 million units. Zillow counted 300,242 lots for sale in June 2026, representing 17.4% of all for-sale listings on the site. The typical listed lot is 0.57 acres — often enough land for more than one home under more flexible zoning rules — which suggests the 6.3% impact estimate is conservative. Permitting timelines and uncertainty that add cost and risk, especially for small and midsize builders working on scattered lots. Zillow framed manufactured housing as a potential tool for turning more of these lots into homes because factory-built units can be produced faster and at lower cost than traditional site-built construction.