Since the early decades of the French Protectorate in Morocco, experts and bureaucrats have sought solutions to a variety of urban crises—from housing and unemployment to public health and anticolonial unrest—in a simple formula: build more houses, build cheaper houses, and employ more workers. Beginning in the 1920s, concrete, asphalt, and sheet metal spread across Morocco's urban landscapes—enabling new approaches to managing urban environments and reshaping residents' practices of building and dwelling. My dissertation research explores the link between colonial concepts of urban crisis and the socio-technical work of remaking Morocco's urban infrastructures by tracing the movements of building materials through different technical systems, ecological relationships, and regimes of value. I will examine how the circulation of materials created "urban crisis" as a historical actor category, a contested object of knowledge, and an approach to governing Moroccan cities. My project focuses on large-scale urban renovations that inspired public and bureaucratic debates in cities such as Casablanca and Agadir from the 1920s to the 1960s. By analyzing how experts, officials, and urban residents mobilized materials and arguments about materials to envision and enact political futures, this project argues that "technological" solutions to colonial urban problems reconfigured forms of vulnerability and authority during Morocco's Protectorate period and post-colonial transition. As a key site of experimentation for planners and engineers and a transfer point between Europe, Africa, and the Middle East, Morocco also provides an ideal case for examining how knowledge about materials traveled transnationally—creating geographies of imperial power, technological exchange, and shared vulnerability.