Appearing ready to collapse. (Merriam – Webster)
Carelessly or loosely constructed. (Merriam – Webster)
Badly or untidily made and likely to break or fall down easily. (Cambridge Dictionary)
Badly organised. (Cambridge Dictionary)
Loosely made or held together; rickety; shaky: (Dictionary.com)
(especially of a house or vehicle) in a state of severe disrepair. (Oxford Dictionaries)
A ramshackle building is badly made or in bad condition, and looks as if it is likely to fall down. (Collins Dictionary)
Ramshackle run down building.
Ramshackle (III) by Sean T Phelan.
Shack Hut Ramshackle.