A reservoir is built in housetop, have structure of wall of edaphic lay aside, some of alga, fish is put inside, form small-sized ecosystem with assuring water quality fresh.

• 在屋顶建设一个蓄水池，有土壤贮壁结构，里面放些藻类、鱼类，形成小型生态系统以保证水质的新鲜。