A house or a room can never be viewed in isolation. As part of a nexus, architecture creates relationships from houses and interior spaces. Our relationship to designed space is constantly being re-experienced and re-evaluated, most recently during the Covid-19 pandemic, which radically re-evaluated interior and exterior space. Complementing this, structural substance forms a pillar of our understanding of architecture - from the actual material substance in its cycles and transformations to the programmatic content of architecture and the substance of the city. UM_BAU 32 makes explicit this tension between space and substance. UM_BAU invites a diverse range of voices to write about the permanent and the (in)tangible, producing a document of an extraordinary time. Interior and exterior, public and private spaces Current ideas on material cycles and resources With contributions by Stephan Trüby, Elise Feiersinger/Claudia Cavallar and many others. Stephan Trüby on Camillo Sitte in his anniversary year 2023 Andrea Erwig on waiting rooms in literature Dirk Baecker on the structural substance of the city Studio Magic on the value of slowness and on Neuberg College in the former railway station in Neuberg/Mürz Elise Feiersinger and Claudia Cavallar on Hermann Czech, David Kohn and spatial relationships between Vienna and London Maik Novotny and Andreas Vass on new spatial relationships in the pandemic