Buildings with 50 or more units accounted for 57% of the multifamily housing completed in the United States in 2025, according to a National Association of Home Builders analysis of Census Bureau data published July 27 β the highest share since 2021 and the ninth straight year that large buildings have made up the majority of new apartment supply nationally.
NAHB economist Jesse Wade, drawing on the Census Bureau’s Survey of Construction, found that of the 484,000 multifamily units completed in 2025, 278,000 were in buildings of 50 or more units, while the remaining 206,000 were in smaller, low- and medium-density buildings. Total multifamily completions fell in 2025 from 2024’s nearly 40-year high, but the share going toward high-density buildings kept climbing.
The pattern is a reversal from historical norms. According to the analysis, multifamily construction had generally skewed toward smaller buildings with fewer than 50 units dating back to 1972, when the Census survey’s tracking begins. That trend flipped in 2017, and large buildings have accounted for the majority of new multifamily units in every year since.
Regionally, the South led all areas with 217,000 multifamily completions in 2025, of which 56% were high-density; the West followed with 127,000 completions (58% high-density), the Northeast with 79,000 (73% high-density) and the Midwest with 63,000 (40% high-density). The Northeast’s 73% high-density share was the most concentrated of any region, consistent with the dense urban development patterns common in that part of the country, while the Midwest was the only region where buildings under 50 units still made up a majority of completions.
The analysis also broke out multifamily construction by intended use: built-for-rent units made up 461,000 of the 484,000 total completions, or 95%, with 59% of those rental units in high-density buildings. Built-for-sale multifamily units β condominiums and similar for-sale product β totaled just 23,000 units nationally, of which only 32% were in high-density buildings, suggesting for-sale multifamily development remains concentrated in smaller-scale projects.
The findings add construction-side context to a multifamily market that has been digesting a wave of new supply delivered over the past two years. RealtyWire has previously reported on concerns about a coming multifamily supply cliff as completions slow from 2024’s peak, and on metro-level pipeline pullbacks such as Las Vegas’s four-year low in apartment construction activity. NAHB’s data suggests that even as overall completion volume eased in 2025, developers continued concentrating new supply in larger buildings rather than spreading it across smaller projects.
What it means: The unit counts, regional breakdowns and built-for-rent share are NAHB’s tabulation of Census Bureau survey data, a Class 1-sourced government dataset analyzed by a named industry economist β these are verified figures, not estimates. The characterization of a sustained “reversal” toward high-density construction since 2017 is NAHB’s framing of the historical data, which RealtyWire finds is directly supported by the year-by-year majority-share pattern the analysis describes. What to watch: whether the high-density share continues rising as 2024’s record completions pipeline fully works through, or whether slowing overall multifamily starts eventually pull the large-building share down with it. RealtyWire’s analysis: because large buildings generally take longer to plan, finance and build than smaller ones, 2025’s completions largely reflect financing and permitting decisions made one to several years earlier — so this data describes projects launched before the more recent slowdown in new multifamily starts, and may not predict what today’s smaller pipeline of new projects will look like once it is completed.
