AbstractIndustrial symbiosis (IS), where different entities collaborate in the management of energy, utilities, materials, or services, has been identified as an approach to improve resource efficiency and circularity in industry. This article assesses the environmental performance of an IS network with firms involved in waste management, soil, surfaces, paper, lumber, and energy. The aim is to highlight the environmental performance of an IS network and pay particular attention to the improved performance for products in the IS network. Life cycle assessment is used to compare the current IS network with a reference scenario and a potential future development. The results suggest that there are significant benefits from the IS network. Large reductions in greenhouse gas (GHG) emissions and abiotic resource depletion were identified. Furthermore, large reductions in local impacts, namely eutrophication and acidification impacts are illustrated. It was shown that all firms in the network benefit from the synergies involved, with a large share of the benefits stemming from the facilitated exchanges with the waste management company. The replacement of conventional products and energy streams with bio‐based counterparts from within the network is of significant importance. Finally, the results point to the importance of the facilitation of by‐product synergies, and the significant value this creates in the region, with large potential to improve the environmental performance of firms and their products.