Five years to build an apartment

In San Francisco, New York, and Miami, it takes nearly five years from application to completion to build a modest apartment building. That's according to a new economics working paper on housing construction timelines across sixty US cities.

The gap between cities is vast

In Raleigh, North Carolina, a builder can complete a twenty-unit apartment building in about the time it takes just to approve the permit in San Francisco, where applications languish for more than a year.

Single-family homes show the gap too

In Indianapolis, a single-family home can be built in six months from proposal to completion, less than one-eighth the time it takes in San Francisco.

The researchers and their dataset

The authors, Leonardo D'Amico, Evan Soltas, and Audrey Wang, assembled one point one million permits covering two point seven million housing units between two thousand and twenty twenty-five, about one in thirteen new homes permitted nationally over that period.

Permitting times have nearly tripled

Across the cities in their sample, permitting time for a standardized multifamily building rose from zero point six years in two thousand to one point five years in twenty twenty-three. For single-family homes, it rose from one point six months to four point nine months.

Delays have real costs

Longer permitting times are correlated with higher housing prices and lower rates of housing production. Delays also mean lost staff time that developers bake into the cost of new homes, and projects that never get built because the process discourages all but the best-resourced developers.

What permitting actually covers

Permitting refers to everything after a developer submits an application, before they break ground. The proposal is reviewed for compliance with building safety, energy codes, plumbing, zoning, and in some places, aesthetic design. Applications often get sent back for revisions.

The standardized projects studied

Researchers estimated how long an identical, standardized project would take in each place between twenty fifteen and twenty nineteen. Their archetypes were a twenty-eight-hundred-square-foot detached single-family home on a zero point one five-acre lot and a twenty-unit multifamily building with twelve hundred square feet per apartment.

Permitting delays compound construction delays

Cities with longer permitting times also tended to have longer construction periods. The longer it takes to get an application approved, the longer it then takes to do the building itself, which compounds the gap between the fastest- and slowest-building cities.

California's environmental review burden

California has long subjected some housing projects to extensive environmental review requirements under the California Environmental Quality Act, or CEQA. Apartment buildings, especially larger ones, are more likely to have to go through CEQA review, though they are more environmentally friendly than single-family homes.

Approval odds have plummeted

In two thousand, a standardized multifamily project had a seventy-one-percent probability of approval within six months of applying for a permit. In twenty twenty-five, that project had a forty-four-percent approval probability within six months.

“In 2000, our standardized multi-family project had a 71-percent probability of approval within six months of applying for a permit. In 2025, that project had a 44-percent approval probability within six months.”

Zoning codes keep getting stricter

Zoning codes, first widely adopted in the US in the early-to-mid twentieth century, have continued to become more restrictive even in recent years, making it harder to build housing. This dovetails with the finding that permitting times have ballooned across the country.

Building codes may be part of the problem

The slowdown may be connected to expanding building code requirements. Although ever-more stringent rules might seem like a great idea, they tend to be biased against multifamily housing and likely inflate the cost of building, all without having to show that the benefits are worth the costs.

What the delays mean for New York

An apartment building that is okay to build in Grand Rapids today would be safe for New York. Mayor Zohran Mamdani can now put an exact number on the delay that extra permitting time represents for the city.