The construction industry and buildings have a considerable impact on society, ecosystems, and global warming, shaping the way people live, consuming large amounts of materials, and producing abundant GHG emissions. As a result, the building sector plays a crucial role in the fight against climate change by mitigating the industry’s impacts and decarbonizing buildings. Therefore, the concept of Net Zero Carbon Buildings (NZCB) emerges as the answer of the sector’s researchers and practitioners to eliminate or minimize a building’s carbon emissions throughout its entire lifecycle. However, there is no established and clear action plan or set of strategies for construction companies to design, build and operate such buildings. Thus, the purpose of the thesis is to co-design a strategy in collaboration with real-estate development companies to reduce the carbon emissions of their buildings and contribute to reaching NZCBs. For this purpose, this study is based on theories, such as Design for Sustainable Transitions, to comprehend and analyze the industry’s composition, its enablers and limitations, and Participatory Design to engage with key actors and co-create an effective solution. Additionally, research, analytical, and participatory methods like interviews, affinity diagrams, and workshops were essential in the design process to gather relevant information and knowledge, examine connections and pathways, and create spaces for creation, discussion, and evaluation. Finally, this journey led us to develop a practical,Abstractclear, and tailored Guideline for real-estate development companies to implement design and behavioral strategies that reduce the operational carbon of buildings and encourage them to build their own path toward the decarbonization and resilience of the built environment.