A sharp decline in commercial building projects caused a slight decline in overall U.S. construction spending in January, the government reported Thursday. The Commerce Department said construction spending fell 0.1 percent in January to an annual rate of $827 billion, the first drop since July 2011. Spending rose 1.4 percent in December and 1.9 percent in November. Construction of factories, hotels, and power plants all fell sharply, lowering non-residential construction spending by the most in a year. Government spending also declined. Spending on residential construction rose 1.8 percent, driven by a big gain in single-family home building.