Definitions of building:

• noun:   a structure that has a roof and walls and stands more or less permanently in one place

  Example: "There was a three-story building on the corner"

• noun:   the occupants of a building

  Example: "The entire building complained about the noise"

• noun:   the act of constructing or building something

  Example: "His hobby was the building of boats"

• noun:   the commercial activity involved in constructing buildings

  Example: "Workers in the building trades"