2id architects have completed a duplex housing, located in the midst of an industrial district within northern hamamatsu, japan. standing on its own among a number of factories, the building provides shelter to two families: a woman living alone and her son, his spouse and their four children. the architects were required to work out an arrangement for this unbalanced inhabitant ratio, as well as secure an open space for the families to get together.

dan dan dan house 1

all images courtesy of 2id architects



along with the physical limitations of the site concerning the reclamation of the external environment, 2id architects deliberated on the openness of the internal space and the control of light. in consideration of the ambient surroundings, privacy was ensured by keeping a fixed distance from the outside space. meanwhile, clerestories gather plenty of light and its soft reflection on the wall surface permeates throughout the house. closeness and openness are two contradicting elements at a glance, yet the design strives for a cohabitation of the closeness and the sense of protection from the outside world with the openness of the diffusion of light. by having these two elements live under the same roof, tranquility was achieved, as well as extensiveness for a pleasant space embracing the big family.

dan dan dan house 2
shared living room



a bright shared living room gathers sunlight through the clerestory and attracts the families, becoming the hub of communication within the house. the light softens itself as it gets carried into the adjoining room, connecting the two independent spaces together and allowing the families to enjoy their private life while feeling each other’s presence. it seems as the light produces interrelationships among the families, becoming a  distinctive element of the duplex housing.

dan dan dan house 3
tatami mat and polycarbonate



concerning the exterior design of the dwelling, three blocks were produced forming a zigzag structure. each block houses a separate function: ‘for the mother’, ‘sharing’ and ‘for the son and his family’. the simple dimensional structure design created space for clerestory while protecting privacy, extensive living space and large-volume underfloor storage and dedicated the second for to the son and his family. the uneven roof created multiple clerestories, resembling the iconic appearance of the factories in the neighborhood.

dan dan dan house 4
spiral staircase



the entire floor of the shared living room is lined with tatami mats. the shared living room has six entrances connecting to other rooms and a spiral staircase connecting to the children’s room on the second floor which make the living room the epicenter of the house. the tatami mats invite the families to sit, lie down, or be in whatever position they may feel comfortable with. the polycarbonate adopted for the wall surface of the living room transmits soft light to connect the spaces, creating a comfortable distance between the families. this inventive combination of tatami mats and polycarbonate enhances the unique extensity of this duplex housing and helps conjure up interactions and interrelationships among the family members.

dan dan dan house 5
kitchen for the mother


dan dan dan house 6
kitchen for son’s family


dan dan dan house 7
the light collected in the living room softens as it gets carried into the adjoining room


dan dan dan house 8


dan dan dan house 9
children’s room


dan dan dan house 10
children’s room


dan dan dan house 11


dan dan dan house 12



project info:


name: dan dan dan house

architecture office: 2id architects

lead architect: tsukasa okada




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edited by: myrto katsikopoulou | designboom