The costs of defects and quality issues in construction can be significant for stakeholders and can include societal consequences. The aim is to address how failures and defects are produced and handled in the social practices of construction projects and specially to scrutinize the unintended consequences of both structured and chaotic problem solving. The argument is based on a longitudinal ethnographic study of a dwelling project, encompassing just over 100 days of fieldwork. Structuration theory was applied to understand the interrelations between project actors and structures in the handling and redressing of quality issues and to elucidate unintended consequences of the practices. The analytical strategy was abductive, allowing theory and empirical material to inform each other. Two cases were selected; the well-structured process of erecting concrete panels and the chaotic processes of building a penthouse. The results show how routine and experience are helpful, but also how they maintain an “acceptable” level of defects, which should change the widespread appreciation of experience as being positive for building quality. The unintended consequences of routinized practices are corroborated by the lack of knowledge sharing beyond the project. Both reactive and proactive problem-solving practices are important, but the reactive tend to dominate.