Facilitators and barriers to planning integration: Insights from Multi-plan Integration in China

Integration in spatial planning remains a persistent challenge, especially amid growing environmental and societal complexities that demand coordinated solutions. While much research highlights facilitating factors for integration, less attention has been given to barriers that hinder cohesive planning, particularly within centralized governance contexts. This paper addresses this gap by investigating how Multi-Plan Integration (MPI) operates in practice within Chinas spatial planning system. Through a comparative case study of three MPI projects and one non-MPI project, we identify the effects, facilitators, and inhibitors of integration. Findings reveal that MPI can improve integration outcomes when supported by enabling institutional, instrumental, and contextual conditions, such as collaborative networks, effective process management, and adequate resources, but it does not guarantee success due to persistent challenges including fragmented expertise, low capacity of connective actors, and limited collaborative culture. Importantly, integration emerges not solely from top-down mandates but through bottom-up coordination, informal communication, and adaptive governance practices. This study contributes to spatial planning literature by highlighting pathways to integration in hybrid governance systems and provides an analytical framework for understanding the complex dynamics shaping planning integration. • MPI improves integration outcomes when accompanied by enabling contexts and tailored strategies. • Facilitators include supportive contexts, positive collaboration history, and suitable governance structures. • Inhibitors include fragmented planning teams, limited connective capacity, and unintended consequences of past history. • Integration arises not solely from mandates but also through bottom-up coordination, informal communication, and adaptive governance. • Planning is a complex, iterative, and multi-directional process across actors and authority levels.