U.S. population growth slowed notably in the latest population estimates from the U.S. Census Bureau, with the nation expanding by just 0.5% in 2025, roughly half the pace of the prior year. The deceleration was primarily driven by a sharp decline in net international migration, which dropped from 2.7 million to 1.3 million, while natural change remained relatively stable.

Population growth remains concentrated in the South and parts of the West, while many areas in the Midwest and Northeast experienced slower growth or population declines. These forces are not only redefining where population growth occurs but also reshaping the geographic foundations of housing demand.

At the county level, population growth slowed across much of the country, with a majority of the nation’s 3,143 counties and the District of Columbia experiencing decelerating population growth in 2025. Of the 2,066 counties that grew in 2024, nearly 80% saw their growth slow or reverse last year. In many cases, counties already experiencing population loss saw those declines deepen further.

Net Domestic Migration (Americans moving from one county to another) has become the most visible driver of county-level divergence. Population flows continue to shift away from the largest and most expensive counties toward smaller and less densely populated areas.

Collectively, the 50 counties with population exceeding one million recorded a net domestic migration loss of 637,634 in 2025. In contrast, large counties with populations between 50,000 and 999,999 posted a combined gain of 533,766 residents, while medium-sized counties with population between 15,000 and 49,999 gained 95,095. Even the smallest counties, with population below 15,000 residents, recorded a slight net gain of 8,773.

Interestingly, these county-level population trends closely align with the latest fourth-quarter results from the NAHB Home Building Geography Index (HBGI), which tracks construction activity across counties with different population densities. The index shows that single-family construction has weakened across most geographies, with the exception of the least dense markets, while multifamily construction has increasingly shifted toward smaller and lower-density areas.

This pattern underscores a strengthening link between population dynamics and housing market outcomes. In large metro core areas, weaker construction conditions are associated with slower population growth, with 86% of counties also experiencing deceleration. In these higher-density markets, both single-family and multifamily development have moderated, reflecting softer demand and persistent affordability challenges.

Additionally, the HBGI indicates that market share has shifted toward smaller and lower-density areas in both single-family and multifamily construction, consistent with the continued domestic migration inflows. Small metro core and outlying counties recorded a net domestic migration gain of 327,598 in 2025, reinforcing this geographic shift in demand and building activity.

Conversely, counties with stagnant or declining populations are contributing to a softer national housing outlook. Builders in these markets are facing slower absorption, rising inventories, and a more cautious development environment, all of which are reflected in softer HBGI readings.

For more on the analysis of the data, read this in-depth blog post from NAHB Eye on the Economy.