The application of aluminum formwork systems has the advantages of a high reuse rate and low construction waste. It can contribute to achieving global net-zero carbon emissions goals. However, accessing the carbon footprint of aluminum formwork systems can be challenging, especially considering the actual reuse rate of aluminum formwork. To address this issue, this research proposes and implements a carbon footprint assessment model in a BIM-based aluminum formwork layout planning system currently being developed at National Taiwan University. This model is based on Life Cycle Assessment (LCA) and the aluminum formwork inventory management system to identify the sources of carbon emissions associated with the aluminum formwork system in a construction project. After engineers complete the formwork planning, a rapid estimation of carbon emissions during the production, construction, and transportation phases is provided. Engineers can decide their carbon reduction strategy based on the carbon footprint assessment results. This research uses an actual construction project as a case study for validation. The result shows that the proposed approach can rapidly provide a carbon footprint assessment of the aluminum formwork system.