The average length of time to complete construction of a multifamily building, after obtaining authorization, was 15.7 months according to the 2017 Survey of Construction (SOC) from the Census Bureau. The authorization-to-completion time has been on an upward trend since 2013, increasing by approximately one month each year.
The average time to build multifamily homes varies with the number of units in the building. In 2017, buildings with 20 or more units took the longest time (17.6 months) to build after obtaining authorization. Properties with 5 to 9 units required 15.7 months. 10 to 19 unit buildings finished in 15.1 months, and, lastly, 2 to 4 units came in at 13.5 months. Compared to 2016, it took longer to complete multifamily buildings with less than 9 units in 2017. It took additional 1.7 months to finish 5 to 9 unit buildings, and additional 1.1 months for 2 to 4 unit buildings.
The 2017 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, 17.8 months, followed by the West, 17.1 months, and the South 14.4 months. The shortest permit-to-completion period happened in the Midwest with 13.5 months.