This lecture discusses the architectural and urban planning ideologies that emerged in Weimar Germany between 1918 and 1933. It highlights the influence of key figures such as Bruno Taut, Ludwig Hilberseimer, and Ernst May, who contributed to the development of modernist architecture and urban design. The instructor examines the concept of planning as a prerequisite for architecture, emphasizing rationalization, uniformity, and industrialization in design. The lecture also explores the significance of the Garden City movement, initiated by Ebenezer Howard, and its impact on social housing and urban development. Various architectural projects, including the Expansion of Amsterdam and the New Frankfurt initiative, are analyzed to illustrate the practical applications of these ideologies. The discussion extends to the design of living spaces, such as the Frankfurt Kitchen, which aimed to optimize domestic efficiency. Overall, the lecture provides a comprehensive overview of how architectural practices in Weimar Germany were shaped by socio-political contexts and the quest for modernity.