Why do city's buildings age so quickly?

On the corner of two busy roads in Tianjin stands my first place of residence in China. At the time, the apartment building's glistening white tiles made it look like a jewel. Smartly dressed security guards met everyone that entered with an energetic salute and a smile. The parking lot smelled of asphalt and was neatly divided into freshly painted parking spaces. The interior courtyard had a newly-planted garden with rows of promising saplings surrounded by bright, green grass. It all looked very nice.

On a recent visit to the same complex, though, I discovered it doesn't look so nice any more. The white tiles are now more gray than white, with some missing, exposing the cracked concrete beneath. The security guards seem to devote more of their time to chasing rats with brooms than saluting people with a smile. The parking spaces are faded and the asphalt is slick with engine oil. The trees in the courtyard have grown but they are covered with a thick layer of dust, while all the grass is gone.

I was shocked. The whole complex couldn't have been more than 10 years old, but it looked more like 50. The building had aged so fast it reminded me of progeria.