Single-family construction declined further in the fourth quarter in all but sparsely populated micro counties, according to the NAHB Home Building Geography Index (HBGI). Meanwhile, multifamily construction showed growth in all markets for the first time in over two years as it continued to strengthen given the affordability challenges facing for-sale construction. The HBGI tracks single-family and multifamily permits across seven population density delineated geographies in the United States.

Single-Family

Among the HBGI markets, growth in the fourth quarter of 2025 was only registered in micro counties, which increased 1.6% year-over-year on a four-quarter moving average basis (4QMA). This was the seventh consecutive quarter where micro counties showed growth. All other markets reported declines, with the largest occurring in large metro core counties, posting a decline of 12.8%. All markets showed growth one year ago which quickly dissipated as 2025 presented a host of challenges for builders, ranging from the ongoing affordability crisis to economic uncertainty.

In terms of market share, single-family construction’s largest geography remained small metro core county areas, representing 29.4%.. The smallest single-family construction market remained non metro/micro county areas, with a 4.5% market share. The largest decline in market share over 2025 was in large metro core counties, falling one percentage point to 15.1%. The largest gain over the year was in small metro outlying counties as the market share rose from 10.0% to 10.5%.

Multifamily

Matching single-family, the largest gains for multifamily construction occurred in micro counties, growing 14.0% (4QMA) in the fourth quarter. This was followed by small metro outlying counties which grew 11.6%. The lowest growth was in large metro outlying counties at 1.9%. This quarter marks the first time that all markets showed growth since the first quarter of 2023.

In terms of market share, large metro core counties held the largest at 35.1%. The market share for large metro core counties rose significantly over the course of 2025, as it was 33.3% in the first quarter. The area that lost the most market share over the year was large metro outlying counties, falling from 4.7% to 3.7% in the fourth quarter.

The fourth quarter of 2025 HBGI data along with an interactive HBGI map can be found at https://nahb.org/hbgi.