This master's thesis explores the role of policy innovation of policies, programs, and policy instruments within the domain of heat transition in the built environment in the Netherlands, focusing specifically on the role of municipalities in navigating this complex transition towards a natural gas-free future by 2050, as mandated by the National Climate Agreement (2019).

Introduction
The research starts by outlining the ambitious goal of the Dutch government to significantly reduce CO2 emissions by 2050, emphasizing the critical target of reducing natural gas usage in the built environment in the Netherlands. The introduction highlights the urgent need for innovative policy approaches to accelerate the heat transition, especially in light of geopolitical factors such as the crisis in Ukraine, which underscore the urgency of energy independence.

Theory
Starting with a literature review regarding the different conceptual defnitions of (policy) innovation and the framework provided by Schaffrin et al. (2015), the study delves into the concept of policy innovation, exploring its significance in the context of the heat transition in the built environment. The research identifies the multifaceted nature of innovation, encompassing the novelty of policies, their adoption, and eventual impact. The theoretical foundation emphasizes the importance of analyzing policy output to gauge the extent of innovation within municipalities' strategies for the heat transition.

Methodology
An exploratory study design using qualitative research methods is outlined, focusing on a case study analysis of Transition Vision Heat (TVH) documents from ten of the most populous municipalities in the Netherlands. The research adapts and modifies Schaffrin et al.'s (2015) framework to assess policy output and innovation to fit the context of the heat transition in the built environment in the Netherlands, employing Atlas.ti software for document analysis. The methodology section discusses the selection criteria, data collection, and analysis processes, highlighting the study's systematic approach to evaluating policy documents.

Results
The results section presents a detailed analysis of policy output across eight categories, revealing a spectrum of innovation levels among the analyzed municipalities. Amsterdam is noted for its high scores in integration, target groups, and alternative technologies, showcasing a proactive approach to the heat transition. Furthermore, TVHs were scored using the modified framework of Schaffrin et al (2015). This research identifies significant differences in policy integration, stakeholder involvement, and the specificity of alternative solutions across municipalities. Despite these differences, commonalities include a shared commitment to updating the TVH every five years and aiming for a gas-free environment by 2050.

Conclusion
The thesis concludes that while Dutch municipalities exhibit a range of innovative strategies in their approach to the heat transition, there is room for improvement, particularly in setting concrete targets and detailed implementation procedures. The study advocates for municipalities to take a more directive role in leading the heat transition, emphasizing the need for tailored and innovative solutions that reflect local contexts. The research suggests that a comprehensive, collaborative, and context-specific approach is essential for successfully navigating the complexities of the heat transition toward a sustainable, natural gas-free built environment in the Netherlands.

Discussion
The discussion emphasizes the scientific added value of adapting Schaffrin et al.'s (2015) framework to the context of the heat transition in the built environment, underlining the importance of scope on alternate technology solutions and the target groups involved. Limitations such as the subjective nature of measuring policy innovation and the representativeness of the sample size are acknowledged. The section also suggests the need for future research to include broader samples and expert validation to enhance the framework's reliability. Furthermore, the role of local initiatives and the inclusion of residents' opinions and viewpoints in TVHs are emphasized as crucial for developing tailored, context-specific policy solutions. The involvement of residents (e.g., in the form of communities) can contribute to a more appropriate approach that contributes to the advancement of the heat transition in the built environment in the Netherlands.