Location: Hiroshima, Japan.

Architect: Hiroshi Nakamura + NAP.

This house is sited among tall buildings in downtown Hiroshima, overlooking a bustling street. To obtain privacy and tranquillity, a garden and optical glass façade was placed on the street side, visible from all rooms. Glass casting was employed to produce a glass of extremely high transparency from borosilicate, the raw material for optical glass. This façade allows residents to enjoy the changing light and city moods, and live in awareness of the changing seasons. The casting process was difficult, requiring both slow cooling and high dimensional accuracy.

To create a transparent façade, 75 stainless steel bolts suspended from the beam above the façade were strung on stainless steel flat bars at 10-centimetre intervals. The supporting beam, if constructed of concrete, would be of massive size, so pre-tensioned the steel beam and gave it an upward camber, then cast concrete around the beam to minimize its size.