Architects: Koichiro Horiuchi
Location: Inokuchi, Nishi Ward, Hiroshima, Hiroshima Prefecture, Japan
Area: 132.0 sqm
Project Year: 2013
Photographs: Jin Hosoya
From the architect. The site is located in the middle of hill that was developed 50 years ago. It takes 30 minutes from the center of Hiroshima City by car. The center of Hiroshima city locates in the narrow delta, so that almost all the residential area is in the hills around the Hiroshima delta. This site also locates in that kind of hill obtains view around Seto Inland Sea, and it is very common environment in the residential area around Seto Inland Sea. The client moved to this land, retired and determined to live in their rest of life.
‘NAGI’ is a common word expressing the climate of Seto Inland Sea. Wind from sea pass though under below of heated air in the land in a day, and cooled air from land go through under the heated air in the sea at night. From 5pm to 7pm, however, the temperature of air in the land and sea become same, and then flow of the wind stop completely. This uncomfortable humid climate is called ‘NAGI’. How we can solve this uncomfortable environment is the most crucial theme in this region. The most important request from this client is also how we can design comfortable house without air condition in summer.
Four Inner Gardens: Four Inner Gardens are installed in this house. Plenty of winds pass though these 4 garden in every rooms, and creates blight environment without air conditions and lightings.
Center void and openings connecting 1st and 2nd floors: Not only natural ventilation but mechanical ventilation is installed in the top of center void using chimney effect. To attain this effect, several openings are installed in between 1st floor and 2nd floor. These spaces are separated and connected each other. That is not only for the thermal environment, but for the comfortable communication for occupants.
Pit Ventilation System: The ventilation system uses the pit of under floor. The hot air is cooled down in summer and cold air is warmed in winter through the pit ventilation system.
Solar Water Heating System: Solar water heating system is installed for water area including bathroom.
The design is like stacking small box irregularly. That is caused by creating comfortable thermal environment and occupants’ communication. Every space is connected by voids and openings, and occupants always feel family in this house.