The average length of time to complete construction of a multifamily building, after obtaining authorization, is 17.4 months, according to the 2020 Survey of Construction (SOC) from the Census Bureau. The authorization-to-completion time in 2020 was relatively unchanged from 2019, slowing down the upward trend since 2013.

The average time to build multifamily homes varies with the number of units in the building. In 2020, buildings with 20 or more units took the longest time (19.7 months) to build after obtaining authorization. Properties with 5 to 9 units required 18.4 months, as it took extra longer, 28.2 months, to build 5 to 9 unit buildings in the Northeast in 2020.10 to 19 unit buildings finished in 15.7 months, and, lastly, 2 to 4 unit buildings came in at 14.7 months. Compared to 2019, it took longer to complete multifamily buildings, expect the 10 to 19 unit category, 2020. It took additional 0.4 months to finish 2 – 4 unit buildings, additional 1.8 months for 5 to 9 unit buildings, extra 0.7 months for buildings with 20 or more units. However, it was three months shorter to finish buildings with 10 to 19 units in 2020 than in 2019.

The 2020 SOC data also shows a significant regional variation in the average construction duration of multifamily buildings. The Northeast had the longest time from authorization to completion, 19.0 months, followed by the West, 17.6 months, and the South – 16.8 months. The shortest permit-to-completion period happened in the Midwest with 16.5 months.