Before construction begins on new homes in the United States, prospective builders must navigate a complex and often protracted permitting process. A recent study conducted by researchers Leonardo D’Amico of the University of Chicago and Evan Soltas and Audrey Wang of Princeton highlights significant variations in permit approval times across U.S. cities and their broad impact on housing supply and affordability.
The report finds that in cities like Orlando, Phoenix, and Raleigh, North Carolina, the total time from permitting to construction completion for a single-family home averages about one year, while multifamily projects take roughly two years. In contrast, cities such as New York, Los Angeles, and San Francisco face much longer timelines, with single-family homes requiring approximately 2.5 years and multifamily developments taking up to four years to complete.
The differences are striking when comparing cities side by side. Applicants submitting permits simultaneously in Miami, San Francisco, or Boston—the cities with the longest delays—could expect to remain stuck in bureaucratic review long after those filing in Indianapolis, El Paso, Colorado Springs, Phoenix, or Fort Worth have moved into finished homes.
A significant portion of the delay—between one-third and nearly half in the slowest cities—is attributed to waiting for approvals from municipal officials. Moreover, these delays tend to extend overall construction periods, as builders take longer even after permits are granted. This extended timeline contributes to housing shortages and elevated prices.
The researchers quantify the impact on rents, finding that permitting durations explain 51 percent of variations in rental costs across metropolitan areas. An additional year of permitting delay corresponds to a 39 percent increase in rents. These associations remain robust after adjusting for factors such as population density, education levels, and household incomes.
Despite advances in technology, permitting times have generally increased over the past two decades. Between 2000 and 2023, the average time to permit multifamily projects rose from 0.6 to 1.5 years, while single-family permit times more than tripled, increasing from 1.6 to 4.9 months. The likelihood of multifamily projects being approved within six months dropped from 71 percent to 44 percent during this period, and single-family project approvals within two months fell from 88 percent to 70 percent.
Proponents of city planning departments often cite heavy workloads as a cause for delays. However, the study indicates that even during periods of reduced permit applications—such as after the 2007-2009 Great Recession—approval times improved only marginally, suggesting that systemic inefficiencies and a risk-averse regulatory environment are key drivers of the slow process rather than staffing shortages or application volume.
The housing impact is significant, as permit-related delays dampen supply when demand and prices rise, undermining the natural market response. The researchers suggest that municipalities could adopt reforms to accelerate permitting without sacrificing safety, including digital submissions, artificial intelligence-assisted initial reviews, fixed deadlines for agency responses with automatic approvals if missed, third-party code certifications, and elimination of redundant reviews.
Rather than investing in costly subsidies or programs, the study concludes that streamlining approval processes could help alleviate housing shortages by enabling Americans to build homes more swiftly and efficiently.