Digital platforms are transforming sustainability transitions in the built environment by enabling collaboration, transparency, and efficiency. This study examines how these platforms are implemented, adopted by practitioners, and create value for industry stakeholders using the DART (Dialogue, Access, Risk-benefit, Transparency) co-creation framework. Using ethnographic methods and semi-structured interviews, we consider the case study of a Dutch digital platform provider specializing in modular wooden construction. The findings highlight major challenges in sustainability transitions, including industry complexities, inefficient practices, and resistance to change. Five key practices emerged: defining a clear platform vision, improving processes, leveraging digitalization, ensuring scalability, and fostering co-creation. These practices are synthesized into an iterative framework that extends the DART model, illustrating the interplay between digital, social, and physical elements in construction. By embedding DART within a sector-specific model, this study offers a novel perspective on digital platforms as enablers of sustainability. Ultimately, these platforms promote stakeholder collaboration, enhance transparency, and contribute to sustainability goals, such as carbon reduction and circular construction.