Construction on 4.4 million affordable housing units has begun, accounting for roughly 70 percent of the 6.3million units planned for the whole year, the Ministry of Housing and Urban-Rural Development said Wednesday. As of the end of June, construction had been nearly completed on 2.36 million units, and a total of 495 billion yuan had been injected into the affordable housing program, the ministry said. The affordable housing program, which was approved in 1999, is designed to provide cheaper housing to low-income families who have been edged out by runaway real estate prices. The government has vowed to build 36 million affordable housing units during the 2011-2015 period.