As the UK and Scottish governments aim for zero-carbon housing, with tightly sealed building enve- lopes becoming paramount, indoor air quality (IAQ) and its implications for health has become a con- cern. This context relates to a 2008–2011 study, ‘Environmental Assessment of Domestic Laundering’, concerning the prevalence of passive indoor drying (PID). Assessment of PID impacts, shaped by built and social context including occupants’ habits and trends, draws on monitored data from 22 case studies out of a wider survey of 100 dwellings in Glasgow. The smaller group included analysis of air samples and provided scenarios for enhanced dynamic modelling via laboratory work on moisture buffering. The evidence suggests PID has important implications for energy consumption and IAQ; in the latter case because moisture levels are likely to boost dust mite populations and concentrations of airborne mould spores. Thus, findings indicate possible negative impacts on health, and the paper recommends amended standards allied to design guidance for improved practice, as well as further work related to volatile organic compounds.