"coniwa" is a cooperative house, located in the suburb of western Tokyo.

It is consist of eleven dwellings arranged around a lush courtyard covered by a wooden boardwalk.

In this project, at first a skeleton frame in plan was provided to the potential residents. Afterwards an infill design was developed based on this skeleton frame.

In the first phase of designing; the skeleton plan, we set a high value on the south direction, because in Japanese residence, a south window is popular in most cases. Through programming of the volume, the suitable frame spans for every floor became unique for each residence.

To satisfy this conditions, we designed a structure system with elliptical arches which allow for a wide opening facade in the south direction and maintain a balance of floor loads.

In the second phase of designing; the infill design, the structure frame had been slightly changed as following interior requests and final frame shape was decided.

This structural frame has become the main aesthetic feature of the building defining both the exterior façades and interior spaces.

The building expresses modern atmosphere rather than old-fashioned whilst making use of arches which are classical structure elements.

Each dwellings is placed to face rich outdoor spaces; terraces with wooden boardwalk, green gardens with various plants. These spaces are served as an oasis for inhabitants and useful for a privacy protection.

The central courtyard draws these outdoor spaces together providing a comfortable common space for all residents.