A sustainable refurbishment is an important approach toward reaching the EU’s climate goals. Some challenges of transforming housing areas are few high-quality standards, lack of funding, and low residential interest. This paper aims to present the process of establishing the Sustainable Accounting Standard (SAS) project, led by the Housing Federation of Norway (NBBL), representing 41 cooperative housing associations with 1,186,000 members. Therefore, a need to develop a standardized process for evaluating the possibilities of sustainable refurbishment is in focus. A triangulating combination of literature review, survey, and interview is chosen. The literature review forms a theoretical basis within the field. The design and experiences of SAS are reflected through interviews with project participants from cooperative housing associations and a survey of residential board members from selected pilot projects. The project presents the findings from developing the SAS tool and various stakeholders. The SAS tool forms an improved process for sustainable development in housing co-operatives, addressing all aspects of sustainability, the early involvement of stakeholders, and the importance of residents’ participation. The SAS contributes to a smoother refurbishment process by properly prioritizing improved measures.