This chapter aims to contribute to a better understanding of how sustainable development (SD) can be supported in the building of age-friendly smart living environments (SLEs) to meet the needs of an increasingly ageing population. The proposed holistic analysis framework enables regional stakeholders engaged in building age-friendly SLEs to analyse the identified conditions and practices facilitating and encouraging knowledge collaboration (KC) and knowledge sharing (KS) that are key determinants of knowledge management (KM) and decisive means in supporting SD. Drawing on multiple criteria decision-aid (MCDA) approach, the framework was developed by involving representatives of regional stakeholders, who are innovation actors of the Häme region’s (Finland) quadruple innovation helix model, Quadruple Helix, into a collaborative decision-making process within two empirical studies. The pilot study provided a substantial background for a deeper exploration of multidimensional, complex research questions and context in the main study which utilised problem structuring methods and techniques such as strategic options development and analysis (SODA), cognitive mapping, nominal group technique (NGT), and multi-voting. Assuming a constructivist, process-oriented stance, the main study enabled the development of a more realistic analysis framework through the sharing and aggregating of stakeholders’ expertise and experiences and the uncovering of the cause-and-effect relationships among factors related to the topic under study. Taking the form of a collective cognitive map, the framework was validated by both the regional stakeholders engaged in the decision-making process of the main study and two external experts, who represented business organisations building age-friendly SLEs. Both studies revealed senior citizens’ genuine enthusiasm and motivation to be engaged in building age-friendly SLEs and the vast potential they have in developing collaboration and sharing their knowledge and experience with other stakeholders.