In the context of healthcare buildings, it is necessary to consider a larger number of different aspects than in other building types, as patients' emotions, comfort needs and the integration of latest technologies. In order to introduce sustainable practices in this type of buildings it is necessary to take actions in two main life-cycle stages: design stage (to help the decision makers, mainly the design team, to implement solutions that improve building sustainability); and use stage (to achieve a high level of efficiency, by supporting managers and users in the adequate maintenance of equipment and building operation).Therefore, optimizing building sustainability involves various relations between built, natural and social systems and therefore this is only possible through a systematic approach. State of art analysis showed that there is a lack of common understanding on this field and to tackle this, the goal of this paper is to contribute to the better understanding in this context by exposing a proposal for the structure and systems of weights of the sustainability criteria of a new healthcare building sustainability assessment method, the HBSAtool-PT.The used research methodology is innovative since in the development of the list of sustainability criteria it considers the opinion of main healthcare buildings’ stakeholders, the existing healthcare assessment methods and the ISO and CEN standardization works in the field of the methods to assess the sustainability of construction works. Additionally, a methodology to develop the weighting system to be used in the aggregation of the different indicators is proposed and applied to the Portuguese context.As a result, the proposed method is composed of fifty-two sustainability indicators that cover the different dimensions of the sustainability concept to support decision making during the design of a new or retrofitted healthcare building in urban areas.