The building system is very similar to any live creature in the world. For instance, core of the building is structural elements like walls and columns which is skeleton bones in the body. Foundations are feet that unable to stay properly on the ground. Ventilation system is lungs that help you to breath or properly access air inside. Canalization is the digestion system. Heart could be any main spaces in the buildings. It could be concert hall in the amphitheater, or kitchen in the restaurant. Neuro system would be electricity. The brain will be controller center and etc.