jats:titleAbstract</jats:title>jats:pThis article considers Alvar Aalto's two church and parish centre projects in Wolfsburg in light of the architectural, political and sociocultural contexts that framed their design and construction in post-war Germany. The study interrogates how architect and parish came together to build the ecclesiastical complexes of Heilig-Geist (1960–62) and Stephanus (1963–68), and how the parties interacted and engaged with widely debated issues in church architecture and urban planning. Close analysis of the buildings and their design processes, based on site visits as well as the study of architectural drawings and models, shows that Heilig-Geist and Stephanus acquire sacred character primarily through the connections they establish between interior and exterior space. The dynamic between inside and outside relates the buildings to key ideas in contemporaneous church architectural theory concerning inward- and outward-looking church-building, part of the broader discourse on the relationship between the sacred and the profane.</jats:p>