Symbiotic linkages in industry clusters in the form of interconnected materials, energy and information flows, and close proximity provide unique opportunities to develop efficient environmental strategies. The purpose of our study is to examine the practical potential of applying a life cycle approach in strategy evaluations, as the environmental impact caused by industrial symbiosis systems outside the company gates has been scarcely addressed. This is done by evaluating two strategies for an industry cluster in Sweden: (1) to replace a share of the fossil feedstock used in the industry cluster with forest-based feedstock and (2) to improve energy efficiency through thermal energy integration. The environmental impact reduction potential of the strategies is evaluated using life cycle assessment. The ratio between investment cost and reduced global warming potential is used as an indicator to evaluate the cost-effectiveness of the strategies. Results demonstrate the importance of applying a life cycle perspective as the assessment outcome depends heavily on whether only on-site consequences are assessed or if upstream and downstream processes are also included. 20% of the greenhouse gas emission reduction of the energy integration strategy occurs off-site, whereas the forest strategy has the largest reduction potential off-site, >80%.