Why do houses in Qingdao have attics?

Qingdao was once called "red tiles and green trees, blue sea and blue sky" by Kang Youwei, because the houses in the old city were mainly German-style and Japanese-style two-story buildings at that time, and such houses were basically red tiles with spires, which were beautiful among the green trees. This concept has also been continued in urban construction in recent years. It's ugly to turn flat-topped houses into red tiles, so multi-storey houses in Qingdao are mainly spires with attics. A few years ago, some flat-topped buildings specially built attics, mainly to unify the image of the city.

But then again, adding an attic is also good for improving living conditions. Attic design is reasonable, there are many houses with large use area, and some of them are independent property rights.