Chinese migrant workers have become "semi-unemployed" as a drop in the real estate market has cooled the construction industry.

About 503 million square meters of construction work was initiated in the first five months of 2015, while the decrease rate dropped 1.3 percent to 16 percent. About 351 million were related to residential houses, which saw a 17.6 percent decrease.

Although real estate is still managing to attract funds, the growth rate has dropped. Despite raising 3.2 trillion yuan (about $520 billion) in investments, the nominal growth rate still dropped 0.9 percent to 5.1 percent. Of the 3.2 trillion, 2.1 trillion was invested in residential houses. The increase rate was 2.9 percent, which was much lower than last year's 14.7 percent.

The construction industry employed more than 61 million or 22.3 percent of Chinese migrant workers in 2014, according to data from the National Statistics Bureau. Right now, a considerable number of migrant workers are finding themselves "semi-unemployed" in a lagging real estate market.

Construction workers have been "chilling" in a "semi-unemployed" mode, according to a construction contractor called Hu Cheng from Jiangxi province. Hu has been actively seeking construction businesses in east China for the past six years.

Since the Spring Festival, China's New Year in 2015, real estate construction work has seen more halts than starts in Nanchang, the capital of Jiangxi.

"Cranes just stand still out there," says Hu. "It's been half a year and I've worked for only about a dozen days. It used to be about one hundred days in previous years."