Due to climate change, high-emission industries must transform their production processes toward low-carbon technologies. Therefore, steelmakers plan to replace currently operated production facilities long-term. However, production facilities can also be modified to achieve medium-term emission reductions. Against this background, we present a planning model to support decisions about closing or modifying production facilities within production networks for conventional primary steelmaking. The mixed-integer linear programming model aims to maximize the net present value of steelmaking. It incorporates time-dependent emission budgets that initiate the transformation process. Also, plant modifications to reduce specific greenhouse gas emissions are included. Using different climate scenarios, the dynamic transformation of a European steelmakers’ production network is examined in a case study. The results indicate that modifying production facilities is more favorable in the case of site-specific emission budgets compared to global budgets.