This paper investigates the state-of-art for using the DGNB Sustainability Rating System, Life Cycle Assessment, and Life Cycle Costing in the Danish building industry, and how well this use is aligned with the Integrated Energy Design process in refurbishment projects. An optimal method for including all aspects of sustainability in the design process is developed based on a literature review, interviews of professionals, and a mapping of design processes at a Danish architecture firm that specializes in sustainable architecture. Finally, the paper reflects upon the final design process presented in this work, considers what is needed to implement this design process, and envisages the impact of this practice on the building industry.