Industrial Symbiosis is an important component of Industrial Ecology which studies the collaboration and coexistence of companies to achieve mutual benefits. Its concepts have traditionally focused on eco-efficiency and its direct benefits such as costs reduction, resources optimization and environmental impacts reduction. The paper introduces the use of externalities and collaborative networks as tools to amplify the spectrum of opportunities and, consequently, the potential value of Industrial Symbiosis development. Externalities are related to side effects of companies’ decisions and acts. They offer a broader systemic view to Industrial Symbiosis planning and execution. Sustainable value brings up intangible value drivers such as institutional, organizational and relationship capital as well as risk management consideration. It helps companies to visualize the totality of potential value of Industrial Symbiosis.