Affordable housing is an enduring political challenge. Cities have endeavored to set international standards for this important field of architecture since the 1920s. Planners must work within a socially motivated tradition to find exemplary solutions both at the political and architectural level. This building catalogue documents over 130 residential buildings dedicated to affordable housing. It presents floor plans, large photos, key data, and clear diagrams, providing a comprehensive overview of the solutions being tested today. The publication is rounded off with ten affordable housing concepts that were designed as part of the Housing for All competition, organized by the Frankfurt Department of Planning and Housing, the Deutsches Architekturmuseum, and ABG Frankfurt Holding. Renowned architecture practices based in Germany, Austria, Switzerland, the Netherlands, and France were invited to submit design concepts for building sites in the Hilgenfeld area of Frankfurt. These concepts will reignite the contemporary discourse on affordable housing - in Frankfurt and beyond.