Based on the national statistics of Korea, the population of South Korea are expected to drop by 14 million in 50 years [1]. The population structure itself has also changed dramatically since the 1970s, with constant increase of distribution towards the aging society [1]. This means that the way people live in South Korea will change dramatically over the next years. Collective housing—one or more buildings used communally by a variety of users—becomes a great tool for this adaptation, as it can be modeled for both young and old people, and families in communities. After decades of growth, South Korea is now a land full of high-rise apartments, packed in every space of the country [2]. Therefore, it is also a good idea to decrease the height of the buildings by creating low-rise collective housings, which prioritizes space optimization and views for its residents.