Coupled with the dropping general population but the rising statistics of the elderly demographics, Japan was in the challenge of aging society for a long time. Aoyamadai, one of the low-income housing community in Senri New Town, Japan’s first large-scale new town project after WWII, is facing a dilemma situation: on the one hand, after 50 year’s existence, the economically affordable housings need replacement, and the elder communities need fresh bloods; on the other hand, the community is lacking in attraction to young generations, however, the original residents could not afford the cost to transform the existing community into a mixed-age, youngster-attractive one.

How could Aoyamadai regenerate into an open and vibrant community without laying pressure on the former elder residents? In order to achieve this, the concept of “collective space” is put forward. By introducing rent-out spaces in different aspects - public space as well as units, the economic pressures are shared by renters with business demand. Additionally, people who are brought in the community by commerce also play the role in activate the district.

In Japanese society, based on the constant changing of the individual’s society role and constitution of family structure, people’s demands towards their living space also shift. For most of the low-income population, due to their income limits, they spend their lifetime within the same apartment, despite the space sufficiency / insufficiency caused by the increase or decrease of family members.

In addition to this, the public spaces in low-income community are condensed to reduce the housing cost, lead to the lack of communal facilities, public vitality and sociality. In order to solve these problems, the conception “collective space” comes forward. The kernel of the collective space community is rent-out spaces. By providing rent-out lower floors as commercial space and offices, the community is able to balance the selling / renting price of units. More communal spaces are introduced to attract people stream as well as serving for residents. Besides, some of the units are designed with puzzle rooms – an independent room that could be used by owner or rent out for increasing incomes, to accommodate the fluctuate of family members.