["Transactions of the Institute of British Geographers, Volume 51, Issue 2, June 2026. ", "\nShort Abstract\nThis article develops a legal geography of mould by examining how damp and disrepair become legal, evidentiary and spatial objects within rental disputes and eviction proceedings in Germany. Drawing on ethnographic research across more than 200 district court hearings, it shows how mould enters the courtroom not primarily as a habitability issue but as a procedural catalyst that transforms material deterioration into legally actionable rent arrears and grounds for eviction. The article argues that mould functions as a threshold object through which evidentiary norms, judicial reasoning and structural inequalities in housing precarity are produced and made visible.\n\nABSTRACT\nHousing precarity is often understood through economic constraints, investment mechanisms and structural conditions of urban housing markets. Yet, an overlooked dimension of housing precarity is the presence of mould, which frequently appears in district court cases on rent disputes and eviction proceedings. This paper develops a legal geography of mould by examining how mould becomes a legal, evidentiary and spatial object within rental disputes in Germany. Drawing on ethnographic research across more than 200 district court hearings in Germany, I show how mould emerged unexpectedly as a recurrent force in cases formally centred on rent arrears and termination. Because tenants often reduce rent in response to damp and disrepair, mould enters the courtroom not as a discrete habitability issue but as a procedural catalyst that transforms material deterioration into legally actionable arrears—arrears that, once two months accumulate, establish grounds for eviction. The paper's theoretical contribution lies in demonstrating how mould functions as a threshold object through which evidentiary norms, judicial logics and structural inequalities become visible. Mould disputes crystallise broader dynamics: the instability of evidentiary claims, the individualised assignment of blame and the uneven distribution of expert knowledge and digital tools. By tracing how mould travels from damp walls to judicial reasoning, the paper advances an account of how law materially shapes urban housing precarity. In doing so, it positions mould at the centre of debates on displacement, the politics of proof, the uneven distribution of urban habitability and the infrastructural role of legal systems within contemporary housing crises.\n"]