# Enhancing Knowledge on Energy Refurbishment of Buildings and Green Procurement through Living Labs
## 1 Introduction
Living Labs have gained prominence as dynamic research environments where real-world experimentation takes place [27; 28; 29]. These open innovation ecosystems have been utilized across various domains, including energy efficiency and sustainability [30; 31; 32; 33; 34; 35]. Recent studies highlight their effectiveness in fostering collaboration among diverse stakeholders, facilitating user engagement, and driving innovation in sustainable practices [26; 36; 37; 38]. In recent research, Living Labs (LLs) have increasingly been recognized as an effective method for knowledge transfer across various domains. For example, studies have highlighted the role of LLs in facilitating the exchange of knowledge in natural areas, sustainability practices, and technological innovation [39]. Additionally, some contemporary studies have developed assessment frameworks to evaluate how Living Labs contribute to sustainability transitions. However, these frameworks often emphasize the functioning of the LLs themselves, rather than focusing explicitly on the knowledge transfer process [40]. Moreover, other studies have employed methods such as Delphi studies to identify significant gaps in LLs' performance and concluded that future research should focus on addressing knowledge gaps to enhance the effectiveness of LLs in various contexts [31]. While numerous studies address the effectiveness of Living Labs (LLs) and their role in knowledge acquisition, many fail to adopt research approaches that precisely measure the extent of knowledge improvement resulting from participation in LLs [41; 42]. Our article makes a significant contribution by demonstrating, through rigorous evaluation, the substantial enhancement in specific knowledge areas, such as green policies, funding mechanisms, and public procurement, resulting from active involvement in Living Labs. This article focuses on the pivotal question of whether Living Labs have genuinely enhanced the knowledge of their stakeholders in the areas of energy refurbishment and green public procurement. This study aims to explore the effectiveness of Living Labs in enhancing stakeholder knowledge in the areas of energy refurbishment of buildings and green public procurement. This research employs a robust methodological framework, including stakeholder surveys and a series of in-depth statistical analyses such as the Wilcoxon Signed-Rank Test and the Fisher-Freeman-Halton Test, to evaluate the impact of Living Labs on knowledge improvement. By analyzing data across different countries and organizational types, this study provides critical insights into how Living Labs contribute to the broader goals of the European Green Deal, particularly in fostering sustainable practices in the built environment. The findings reveal statistically significant improvements in knowledge, offering a detailed understanding of the extent to which participation in Living Labs enhances stakeholders' expertise in these key areas. The article in Section 2 offers an overview of the adopted methodology and data. Section 3 presents the results, followed by in-depth statistical analyses. Subsequent dis cussions on these results are elaborated upon in Section 4. Concluding remarks from this study are gathered in Section 5.