There are many perspectives from which we can see building systems as biological organisms. The one I would like to present is the human circulatory system with our city pipelines and electric grids. Like our body cannot survive if blood is not pumped to and from the heart, our cities would be unlivable if water and sewerage pipelines were not provided to each building. In this context, we can consider our arteries to be water pipelines and our veins to be sewer systems. Attached is an image of a water pipeline system in a PC game SimCity 2000 that I played as a kid (which is also why I chose to study Civil Engineering!) that I think resembles a human circulatory system.