Abstract
This paper interrogates the relationship between conventional planning and the emerging practice of urban experimentation through the lens of megaprojects. Focused on a low-carbon city project in Shenzhen, China, it illustrates how the project's large spatial-temporal scale facilitates a process of in-situ upscaling of planning innovation. This process involves iteratively trialing and refining novel practices through spatial demarcation and temporal phasing. This mutual constitution of megaprojects and experimentation highlights an urgent need to incorporate spatial and scale perspectives into studying and practicing urban experiments. This paper also highlights the re-negotiated planning paradox between control and flexibility under the experimental paradigm.