The unemployment rate for construction workers actively seeking industry work declined to 9.4 percent in April from 13.2 percent a year earlier, marking the lowest April rate in seven years. The rate has fallen by more than half since April 2010, when it reached 21.8 percent, though during that time, the number of unemployed workers who last worked in construction declined by 1.1 million, and the industry added less than 450,000 jobs.

Contractors added 32,000 workers to payrolls in April, bringing the industry unemployment rate to the lowest April level in seven years. Total employment reached 6.0 million, the highest level since June 2009, according to the Associated General Contractors of America' May 2 report on federal jobs data.

"Contractors have been adding to workers' hours as well as hiring more employees." said Ken Simonson, the association's chief economist. "It is heartening that all categories of construction employers added workers, not only in April but over the past 12 months."

Construction employment totaled 6,000,000 in April, a gain of 189,000 or 3.3 percent from a year earlier, and aggregate hours worked increased by 3.8 percent. Residential building and specialty trade contractors added a combined total of 13,100 workers in April, and 107,900 (5.0 percent) over 12 months. Nonresidential construction grew by 18,600 employees last month, and 81,300 (2.2 percent) year-over-year.

"There is a limit to how much overtime workers can put in, and companies will be seeking to expand employment even faster if the volume of projects continues to grow," Simonson said. "But the huge drop in the number of unemployed former construction workers may make it harder to keep adding employees."

Association officials said that a sharp drop in the number of secondary-level construction training programs over the past several years has contributed to a decline in new entrants to the industry to replace retiring workers.

"If elected and appointed officials don't act soon to improve the quantity and quality of training opportunities for future workers, many construction employers will struggle to find the workers they need," said Stephen Sandherr, the AGC's chief executive officer. "It would be tragic if the construction industry can't fill good-paying jobs because of a lack of trained recruits."