The calculation of this series was changed starting with the June 24, 1960 release date. See Construction Review June 1960, pp. 4-10 for details.
Source: US. Bureau of the Census
Release: New Residential Construction
US. Bureau of the Census, Nonfarm Housing Starts (Discontinued Series) [HOUSTNF], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/HOUSTNF/, August 3, 2015.