This contribution considers some aspects of urban sustainability in its problematic connection to land use. Some experiences on eco-compatible housing systems are reported, as well as some ones on land use that suggest the priority of recovering and regenerating what already exists. Every territorial intervention must preserve instead of dispersing, and potentiate the heritage of relations and collective life that constitutes "the unique social capital skill of a city".
Keywords: Sustainability, Urban Regeneration, Land Use, City, Eco-compatible Housing Systems, Architecture.