In the last years, municipalities' role in protecting cities from climate change impacts has increasingly gained attention due to their proximity to the citizens. Although municipalities have the tools to implement mitigation and adaptation strategies, anchoring these strategies will demand multiple interventions in the urban sphere if municipalities execute all these projects through a siloed approach. Multi-interventions will increase energy consumption, generating more C02 emissions, as well as more mobility disruptions. Therefore, municipalities need to design and execute their projects integrally. Through a literature review and Rotterdam Municipality serving as a case study, this research explores both the theoretical and practicality of how municipalities can effectively apply an integrated infrastructure design approach (IIDA) to enhance climate-resilient infrastructures (CRI). The research found some of CRI's key characteristics and seven implementation lenses of IIDA at the municipal level: functional, transdisciplinary, synergistic, intervention scale, technological, time and finance. Furthermore, a thematic analysis of 22 interviews revealed 19 key factors that influence a municipality's effectiveness in using an integrated design approach. These factors were grouped into six dimensions: human capacity, organisational culture, governance, information and knowledge, project process development, and finance. These findings have been translated into a strategic roadmap, providing practical guidance for municipalities to effectively implement IIDA. The roadmap suggests municipalities need individuals with soft skills such as holistic vision, proactivity, and collaboration. Additionally, fostering an innovative and collaborative culture is essential to enable the development of pilot projects. From the knowledge generated from pilot projects, municipalities can update their standards process.