HousingPermits

Counting rules

Every number on this site is a count of new housing units that a building permit authorized, taken from the US Census Bureau's Building Permits Survey for 2004 to 2025. This page explains, once, what that count means and how each figure on the area pages is computed.

What a permit count is

A local permit office issues a building permit before construction of a new residential building may start. The survey records how many buildings and housing units each permit covers, sorted by building size: one unit (detached or attached single-family houses), two units, three and four units, and five or more units. On this site two- to four-unit buildings are grouped together. A permit says that units were authorized. It does not say they were started or finished; some authorized homes are built late and some never. Additions, alterations, manufactured homes and publicly owned housing are outside the count.

Reported and estimated figures

About 20,000 permit offices are surveyed. Most report every month; for offices that skip months, the Census Bureau fills in estimates ("imputation"). This site uses the estimates that include those fill-ins, which is how the Census Bureau publishes its annual totals. Nationally the estimated part ranged from 5.2% to 9.8% of units a year between 2004 and 2025; each state page gives its own share.

Places without permits

Only places that require a permit are counted. In parts of some states, mostly rural counties, new homes need no permit and never enter the survey. Metro areas where that gap is visible (fewer than one unit per 1,000 residents a year) have no page of their own; they stay in the metro table and in Versus.

Why the series starts in 2004

The Census Bureau widened the set of surveyed permit offices with the 2004 data, and county boundaries in Colorado changed shortly before (Broomfield County was created). Starting in 2004 keeps every year comparable. "Busiest year" therefore always means the busiest year from 2004 to 2025, never an all-time record.

One map for every year

Metro areas follow the delineation the Office of Management and Budget published in July 2023, the one the Census Bureau uses for its own metro tables from 2024. For every year, a metro area's count is the sum of its counties' counts, so a metro's history is not distorted by later changes to its county list. Earlier years therefore differ from the metro tables the Census Bureau published at the time. Connecticut replaced its counties with nine planning regions; we rebuilt its earlier years from town-level permit counts so the regions line up across the whole series. Puerto Rico is not covered.

Rates per 1,000 residents

Rates divide units by the Census Bureau's population estimate for July 1 (Vintage 2025). The five-year rate divides all units from 2021 to 2025 by the average population of those years and by five. Rates are only shown for 2021 onward, the years the current estimates cover.

Computed measures

What is not here

The survey also records the construction cost declared on permits; we leave it out. There are no house prices, rents, forecasts or judgements about where to buy or build on this site.

Sources

Census Bureau data are works of the US government and in the public domain. Data retrieved October 28, 2026.