The initial house provided by the government of Indonesia for low and medium family hence should be in affordable process is called Rumah Inti Tumbuh (RIT). The Indonesian word tumbuh means “to grow”, indicating that these houses are expected to be transformed, as a representation of growing, following to the owners’ financial improvement and spatial needs. This article is based on the second stage of the research on RIT. The first stage of the research observed units in the Condong Catur Public Housing project in Yogyakarta Province, which was initiated in the 1980s. The findings from the first stage prompted a further research question related to the tendency to transform newer public housing. This article discusses the design transformation of public housing units that have been occupied for shorter periods of time than those units featured in the previous study. The current research employed qualitative methods by observing the occupants of the Wonorejo Public Housing project and the transformations they have made to their homes to meet their expanding spatial needs. The observed units had been occupied for less than five years at the time this research was conducted. Data collection consisted of observing the units, interviewing the occupants, and gaining information from secondary data resources such as the literature and the blue print of the initial design. The observation focused on the development direction and zoning pattern of the units. The research found that the occupants tended to maintain the existing zoning, enlarge semi-public and service spaces, and prioritize development at the back of the housing site. The findings of this second stage research show similar tendencies with the previous research; therefore, these trends could be considered predictive factors that could inform initial RIT design.