The 2018 Survey of Construction (SOC) from the Census Bureau shows that the average completion time of a single-family house is around 7.7 months, which in general includes almost a month from authorization to start and another 6.7 months to finish the construction. The time from authorization to completion varies across the nation and depends on the geographic location, metropolitan status, and whether the house is built for sale or custom-built.
Among all the single-family houses completed in 2018, houses built for sale required the shortest time, 7.0 months from obtaining building permits to completion, while houses built by owners required the longest time, 12.5 months. Homes built by hired contractors normally needed around 9.4 months. A large proportion of single-family homes built for sale and custom homes built by contractors on owners’ land began construction within the same month after obtaining building authorizations. However, custom homes built by owners serving as general contractors had a little over one-month lag between obtaining permits and the start of construction in 2018.
The average time from authorization to completion also varies across divisions. The division with the longest time was the Middle Atlantic (10.5 months), followed by New England (9.9 months), the East South Central (9.0 months), the Pacific (8.9 months), the East North Central (8.5 months) in 2018. These five divisions had average time from permit to completion exceeding the nation’s average (7.7 months). The shortest period, 6.6 months, is registered in the South Atlantic division. The average waiting period from permit to construction start varies from the shortest time of 18 days in the Mountain division to the longest one of 40 days in Pacific.
Houses in metropolitan areas, on average, took nearly 7.5 months from permit to completion, which was 1.3 months shorter than those in non-metropolitan areas. This pattern was quite consistent across the nation, except for New England and the Middle Atlantic where the average time to completion in metropolitan areas was longer than in non-metropolitan areas in 2018.
The SOC also collects sale information for houses built for sale, including the sale date when buyers sign the sale contracts or make a deposit. Looking at single-family homes completed in 2018, 27.7% was sold before construction started, 32.3% sold while under construction, 11.4% sold during the month of completion, and 17.0 % sold after completion. The percent of single-family houses completed in 2018 and remaining unsold as of the first quarter of 2019 was 11.7%.
 Homes built for rent are included in the Built for Sale category in the 2018 Survey of Construction.