What is the ruling on an architect designing buildings that include forbidden parts, such as bars in restaurants and hotels, or stores that sell forbidden things, or even cities that contain forbidden places, knowing that professional work requires designing the entire project?

It is not permissible to work in structural or architectural design for places designated for forbidden activities, as this constitutes cooperation in sin and aggression. Allah Almighty says: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." Therefore, it is not permissible to design a place for usury, a dance hall, or a nightclub.