‘Rational’ technological process was a definitive hallmark of a Norwegian prefabrication company Moelven Brug, featured prominently in most of the company’s marketing materials. However, there are far fewer records of how this 1960s strive for ultimate rationality affected the company’s products, the ways labour was thought of and performed, and the daily lives and livelihoods of Moelven workers. Work-studies and managerial accounting implemented by the company in 1957 made away with local craft and dissected labour into discrete units of work that could be measured, managed and rearranged. I argue that it was precisely this deconstruction of work that conditioned the design of Moelven prefabricated products and—as the company introduced conveyor lines in the 1960s—heralded a shift from building to assembly. This presentation thus strives to answer two main questions: how did Moelven production process change in pursuit of ultimate ‘rationalisation’, and what effect did it have on the company’s prefabricated products? The presentation will discuss the role of labour within industrial production of architecture, professionalisation and industrial alienation, process design and representation, the role of new technology and negotiation between people and machines. As Moelven Brug implemented international models of work and process organisation, it assimilated them to the existing conditions and institutions of the Norwegian working life, producing hybrid socio-technological artefacts. This talk is a work in progress on the second chapter of my PhD dissertation, dedicated to the study of Moelven Brug endeavours with prefabrication in the 1960s. Specifically, as the company built schools, housing and community buildings, the thesis explores its complex entanglements both with professional architectural community and policies and institutions of the Norwegian welfare state.