Since the renting is a business, so it has to following rules and even laws. Such as
1) paying tax for rental income. (I've no idea if Zhang's is honest in paying tax)
2) asked permission from town before upgraded the basement into apartments. (I think they did not. There wouldn't be a permission issue to a small house to build so many apartments.)
3) minimum space requirements for each tenant. (5 tenants are undoubtedly too many because the owner's family is living in the same house too. Someone even said the basement is enough for 10 persons, I suggest him/her to read the town's regulation)
1) paying tax for rental income. (I've no idea if Zhang's is honest in paying tax)
2) asked permission from town before upgraded the basement into apartments. (I think they did not. There wouldn't be a permission issue to a small house to build so many apartments.)
3) minimum space requirements for each tenant. (5 tenants are undoubtedly too many because the owner's family is living in the same house too. Someone even said the basement is enough for 10 persons, I suggest him/her to read the town's regulation)