Each year's share of total U.S. home sales between new construction and existing-home inventory. New homes have averaged 12–15% of all transactions; the share has run as high as 21% (1973) and as low as 7% (2011).
We compute new-construction share as new_sales / (new_sales + existing_sales) per year, with both numerator and denominator in equivalent units. The split tells you how much of the housing market clears through builders versus the resale channel.
New construction's share has fallen secularly since the 1970s as the existing-housing stock grew. The 2011 trough at 7% reflected the post-subprime foreclosure flood; the recent rebound to 14% reflects the rate lock-in keeping resale inventory off the market.
units, K or Mmedian, current $30-yr fixed, % APRCensusNARFreddie MacNBER monthly