Buildings, like biological systems, require many individual units to work together to create an efficient, operable building. They must be integrated seamlessly in the way that biological elements tend to naturally in order to make a building effectual.
The power supply to a building is akin to the mitochondria of a cell. It is the powerhouse of the cell, in the same way that power supply is the powerhouse of a building. It allows appliances to run, lights to shine, heating and cooling to function, water to be heated, electronics to work and other systems to be optimal.
The foundation of a building is similar to the legs of humans and animals. The foundation is what grounds the building, and keeps it standing strong and tall. Legs allow animals to ground themselves and stand, walk, run, and stand tall themselves. Both act as the foundation for the rest of the living being or the building.
The empty space within a building is the cytoplasm of the cell. The cytoplasm is what holds all organelles, in the same way that the space within a building eventually holds furniture, and household necessities. Space is necessary in an efficient building, as it gives it function and purpose. Cytoplasm is necessary in a cell to hold the organelles in place.