With almost 20 years experience as a window cleaner, Zhang Shimin has witnessed the astounding urban growth of the Chinese capital. “There was nothing outside the Third Ring Road when I first came to Beijing,” he said, perched on the roof of a 31-story building overlooking the ring road.

Zhang arrived in 1993 as a migrant laborer from a rural area of Sichuan Province. Since then, he’s witnessed many of the traditional bungalows that housed most of the Beijing residents replaced by tall apartment blocks catering to the city’s growing middle class.

With the boom came demands for exterior cleaning as residents could no longer reach the outside of their windows. A few daring migrant workers like Zhang chose to take the risk and dangle down on ropes in pursuit of higher wages.

The most demanding periods of the year are from the middle of March to the end of May; then from the end of September until the bitter cold stops them from working.

The contrast between the humble dwellings of the migrant worker cleaners as compared to the homes they look into everyday could not be greater, but Zhang says he seldom looks into the windows while working. “I won’t compare myself with them while working, we are totally different groups.”

In spite of the ever-expanding buildings, business is not all that it should be. Zhang explains that China’s strict anti-corruption campaign has affected their window cleaning business this year.

“People who were taking rebates in the cleaning projects are holding back now, so there is really not as much [work] as normal,” he said.

Zhang’s high rise career started in Chaoyang district, the thriving business center of Beijing, which was enjoying the soaring property opportunities for the first ten years of the century. Construction work has now expanded around the major axis of the city. New high rise apartment buildings along with the expansion are providing new opportunities for Zhang and his team.