Graduation project for the completion of my Master's degree on Building Engineering of TUDelft. Development of a computational modelling tool for the environmental and financial assessment of Design for Deconstruction principals on steel structures in an early design stage. The tool was integrated into Rhino as an extension of Rhino's plug-in Grasshopper3D, build upon Grasshopper3D's framework and developed into SustainabilityOpen framework developed by BEMNext laboratory of TUDelft.