The 2021 Survey of Construction (SOC) from the Census Bureau shows that the average completion time of a single-family house is around 8.2 months, which typically includes a little over a month from authorization to start and another 7.1 months to finish the construction. Moreover, it took approximately 12 days more in 2021 than in 2020, as supply-side challenges persisted throughout the year. The time from authorization to completion varies across the nation and depends on the geographic location and whether the house is built for sale or custom-built.
Among all single-family houses completed in 2021, houses built for sale required the shortest amount of time, 7.4 months from obtaining building permits to completion, while houses built by owners (custom builds) required the longest time, 12.8 months. Homes built by hired contractors normally needed around 10.5 months, and homes built-for-rent took about 11.1 months from authorization to completion. Across all categories of single-family houses, the time authorization to start took much longer in 2021. Custom homes built for sale or built by contractors on owner’s land had a little over one-month lag between authorization and the start of construction. The permit-to-start time was even longer for homes built-for-rent (1.64 months), which normally began construction within the same month after obtaining building authorizations in the past.
The average time from authorization to completion also varies across divisions. The division with the longest duration was New England (11.9 months), followed by the Middle Atlantic (11.7 months), the Pacific (9.6 months), the East South Central (9.5 months) in 2021, the East North Central (8.5 months), the West North Central (8.3 months), and the Mountain division (8.3 months). These six divisions had average time from permit to completion exceeding the nation’s average (8.2 months). The shortest period, 7 months, is registered in the South Atlantic division. The average waiting period from permit to construction start varies from the shortest time of 23 days in the East North Central to the longest one of 51 days in Pacific.
The SOC also collects sale information for houses built for sale, including a sale date when buyers sign sale contracts or make a deposit. Looking at single-family homes built for sale and completed in 2021, 32.5% were sold before construction started, 43.2% sold while under construction, 12.7% sold during the month of completion, and 9.8 % sold after completion. The share of completed houses remaining unsold was 1.8%.