Spending on commercial property construction in the United States is expected to drop 14 percent this year, The Wall Street Journal reported. As demand for office and retail spaces remains far below pre-recession levels, and credit markets remain tight, the commercial construction sector isn’t expected to grow until 2012, according to a new report by Standard & Poor’s Ratings Service. The office market is among the hardest hit this year with a 23 percent drop in office construction starts as measured by square feet.