Introduction. The fast development of technology and medicine influences the functioning of healthcare facilities as health promoter for the society, making the flexibility a fundamental requirement. Among the many ways to ensure adaptability, one that allows change without increasing the building’s overall size is the Open Building approach. Methodology. Starting from the analysis of the State-of-the-Art and many case-studies, eight parameters of evaluation were defined, appraising their relative importance through a weighting system defined with several experts. The resulting evaluation tool establishes in what measure healthcare facilities follow the Open Building principles. Results and discussion. The tool is tested to ten case-studies, chosen for their flexible features, in order to determine his effectiveness and to identify projects’ weaknesses and strengths. Conclusions. The results suggest that many Open Building’s principles are already in use but, only through a good design thinking, it will be possible to guarantee architectures for health adaptable for future social challenges.