<p>What can sociology contribute to housing studies carried out across the various fields? Previous sociological studies have answered this question by analyzing housing in relation to different social contexts such as politics, the economy and the family. However, these types of studies limit the possibilities for analyzing housing as building. To better understand the housing itself, we will consider the scientific practices associated with healthy housing during the early Showa period from the point of view of Actor-Network Theory. In particular, we will focus on the work of Koji Fujii - the pioneer of the environmental engineering in Japan. The conclusions of this paper are as follows: the concept of healthy housing developed during the early Showa period resulted from collective scientific practice by many human and nonhuman actors. First, we can see that Fujii produced the knowledge of the environmental engineering by combining the knowledge of hygieiology with his own data derived from observations and experiments.In addition, based on this knowledge, he then developed healthy housing in which the wind and sunlight could be manipulated by means of housing design considerations such as floor plans, equipments and building materials, and then further, extended and expanded on these ideas through his involvement in judging various design competitions. However, the healthy housing was not just the creation of Fujii acting alone, but also relied on input from various social organizations (meteorological observation stations and architectural associations, newspaper companies, electric railway companies) and nonhuman contributions (technologies such as observation equipment and construction equipment, and various natural elements such as sunlight, wind and climate). These results indicate that there is a need to recognize that the process of building healthy housing is the product of the collective scientific practice. This is a significant consideration regarding the adoption of new knowledge in the field of housing studies.</p>