The WELL certificate offers advantages for healthcare housing development of the future. As a consequence, new and unknown challenges within the field of the built environment arise. Moreover, there are uncertainties within the behavioral responses of an ageing population and, among other things, the willingness and benefits to invest in a WELL certificate by an institutional investor and developer. There is a lack of extensive knowledge about the contribution of a WELL certificate to healthcare housing development. In this study, the relative preferences for a WELL certificate in healthcare housing were compared to an ageing population in Delft and The Hague. To establish this, a face-to-face interview in combination with a structured questionnaire was held. Based on the response of 23 respondents, the demographical, social (healthcare housing requirements and preferences) and economical dissimilarities are evaluated. Moreover, the preference for a WELL certificate is also estimated by the institutional investors. To establish this, also a face-to-face interview in combination with a questionnaire was held. Based on the response of 4 respondents, the interest to invest in healthcare housing, the healthcare housing requirements, the financial components and the interest in a WELL certificate are evaluated. At this moment it can be argued that the WELL v2 certificate creates more advantages than disadvantages for the different stakeholders during both the development and exploration phase in healthcare housing. On the other hand, based on the estimated results, it can be concluded that more recognition must arise about a WELL certificate by both the ageing population and institutional investor. The results show that there are differences regarding the preference for a WELL certificate between the ageing population and institutional investors. The ageing population with a higher education level, who exercise more than three times a week, who have a healthy eating pattern and who are more satisfied with the quality of their appartement, apartment complex and neighborhood are found to receive less utility for a WELL certificate. This effect is strong for both men and women. The higher educated ageing population living in social rental housing share this idea compared to the lower educated ageing population in social rental housing. The majority of the ageing population prefer a few WELL concepts, in particular the lower educated ageing population. Moreover, institutional investors claims that investing in healthcare housing is less risky compared to offices and regular housing developments. Nevertheless, not enough healthcare homes have been realized yet. Besides this, the institutional investors argue that a WELL certificate in healthcare housing does not improve the GRESB score. This argument is strong for all institutional investors: no distinction regarding professional position. Furthermore, institutional investors show a higher preference to implement all WELL concepts in contrast to the ageing population. The result shows more preference for a certificate: investors are eager when a certificate can be obtained. The estimation of the results increases the understanding of stated preferences of a few WELL concepts in healthcare housing development. To conclude, from a scientific perspective, this research contribute to the understanding of institutional investor and an ageing population choice behavior regarding WELL certificate in healthcare housing. In addition, it contribute to a potential ex-post study of an ageing population living in healthcare housing. Besides the scientific perspective, this research also contribute to the practical relevance were the behavior of two different social groups within the ageing population will be investigated regarding the social rental, free rental and owner-occupant sector. Additionally, this research contribute to the understanding of the current preferences for a WELL certificate complementing healthcare housing without a WELL certificate.