hamada design tops japanese house with rhombus-patterned galvalume roof

a house with a large galvalume steel plate roof

located in japan’s sakai city, osaka prefecture, this family house by hamada design stands out from its surroundings thanks to a large, rhombus-patterned roof made of galvalume steel. the project serves as an extension of the main building, located on the west side of the site, which is topped with a traditional irimoya roof (east asian hip-and-gable roof). the two structures share an open courtyard, and are loosely connected via a wooden deck that wraps around one of the new building’s corners. the deck serves as an outdoor terrace that remains protected from the elements thanks to the roof’s extended overhangs.

all images by yohei sasakura

hamada design connects interior and outdoor courtyard

hamada design’s project is located in an area of sakai city where traditional and modern constructions coexist. made of a large galvalume steel plate with a rhombus pattern, the roof that tops the building is shaped in a way that allows it to guide the natural light towards the courtyard. meanwhile, a comfortable living space is created under its eaves where the family can enjoy being outside while remaining protected from rain or harsh sunlight.

inside, the japanese architecture studio has placed a communal area on the west side of the house, where the courtyard is located. the space under the eaves where the kitchen, living and dining rooms are located is connected to the outdoor wooden deck through floor-to-ceiling openings. on sunny days, these fittings can be opened to integrate the two zones, creating a continuous flow between inside and outside.