Most of the existing building stock high resources consumption and low indoor environmental quality, leading to the unsustainability of the built environment. It is then urgent to define guidelines that could support the sustainable refurbishment design of buildings since the earlier stages, in order to meet European goal to achieve Nearly-Zero Energy consumption standard in buildings in 2020. This paper presents the process of sustainable building refurbishment, applied to a case study, and defines guidelines to optimize the sustainability of a residential building. To achieve this goal, the definition and evaluation of a group of procedures to be implemented, and a cost-benefit analysis applied to a case study was performed.