Parking minimums add $25,000-$60,000 per unit to housing construction costs, with Seattle developers saving an estimated $537 million after reforms

Municipal zoning codes in most U.S. cities still mandate minimum numbers of parking spaces per residential unit -- typically 1 to 2 spaces -- forcing developers to build structured or underground garages costing $25,000-$50,000 per above-ground space and over $60,000 per underground space, costs that are passed directly to renters and buyers regardless of whether they own a car. Why it matters: These mandated construction costs inflate housing prices by 10-20% for affordable and workforce housing projects, so fewer units pencil out financially and developers build less, so housing supply falls further behind demand in already-constrained markets, so rent growth accelerates and displacement increases in cities like Los Angeles, San Francisco, and New York, so low-income residents who are least likely to own cars end up subsidizing parking infrastructure they do not use. The structural root cause is that parking minimums were codified into zoning ordinances starting in the 1950s based on peak observed demand at suburban sites, and they have become politically entrenched because incumbent property owners and neighborhood groups fear spillover street parking if requirements are reduced. Despite strong evidence -- Buffalo saw 68% of new homes permitted after its 2017 Green Code reform that would have been illegal under prior zoning, and Minneapolis saw a 20% decline in adjusted rents after eliminating single-family zoning and parking mandates -- over 90% of U.S. municipalities still enforce minimums because reform requires politically difficult zoning code overhauls.