Construction hiring is picking up as Americans invest in renovating their homes amid signs that the worst of the housing market declines may be over. The number of people working in residential remodeling in December grew 5.8 percent to 250,700 compared with a year ago, based on preliminary data released Feb. 3 by the Bureau of Labor Statistics. This was the highest growth for these jobs, which account for about 5 percent of construction employment, since December 2006, before the housing bubble burst. Sales of existing homes, which rose 4.3 percent in January, precede spending on improvement projects by about six months, as new owners often do a lot of “fix-ups” soon after they move in, said Kermit Baker, a senior fellow at Harvard University’s Joint Center for Housing Studies. That means there’s now a “strengthening market” for this work, buoyed by demand that’s more discretionary in nature, such as minor kitchen remodels, and by mild winter weather in much of the United States. “More remodeling projects are going to create more jobs in the construction industry,” said Baker, who also is the chief economist for the American Institute of Architects.