The Ceremonial House in the Japanese Garden is called Korokan (鴻鵬館) which means a place of rest and shelter for travelers. All the materials used for building the Ceremonial House have a natural origin: natural stone, wood, bamboo, clay and paper. For the roof we used clay tiles and (red) copper roof slates.
The entrance hall is the only room that has a hardened floor and therefore can be entered with shoes. The tea ceremony room was created in western style where you can sit on benches instead of the traditional Japanese style of sitting on your knees on the tatami mats.
The reception room and living room are both covered with tatami (畳), the traditional carpeting of Japan. The living room is open, this is not only because of the hot and humid climate of Japan whereby the Japanese preferred open rooms to let in a nice breeze. More important is the relation between the room and the surrounding nature. The use of sliding doors makes it possible to create an inner room that is completely integrated with the surrounding garden and the landscape. The openness allows to experience the nature from inside the house. The Japanese garden tradition emphasizes the experience of admiring the garden from inside a living room with the far reaching landscape in the background. The entrance, porch and living room as such become one with the Garden.
From the Japanese house you can barely see the roof as it is obscured by the paper walls and the overhanging roof. As such you can only experience the Garden and the landscape through a horizontal framework. This horizontal experience is very different then our own Western style which focuses on a vertical viewing experience. This is because in the West the experience focuses on the outreach to God which represents the entire universe. The goal of the Western aesthetic is to reach God and heaven: eternity as such is experienced through a vertical framework. This is different from the Eastern traditions and religions where they don't necessarily strive for heaven. They emphasize the horizon and the infinite. For them the universe is like a circle, that knows no beginning nor end.
The wide overhanging roof exists to protect people from the rain, but its primary function is actually the protection from the sun. With the overhanging eaves the Japanese design prevents the sun from entering the inner room and as such prevents it from becoming very hot inside. You would think this makes the inner room very dark, but through its design the inner room is lit up through the use of reflecting light from the surrounding pond. This method also prevents the existance of hard shadows in the room and gives it a warm and lit up atmosphere.
Not only the visual contrast between the indoors and the outdoors is important in the Japanese traditional architecture. Other sensory experiences are as important. The wind can easily blow throughout the building and multiple openings in the roof and floor. Because of this the residents will always experience to sound of the wind. Also the sound of the rain is embraced instead of muffled through different building techniques. They even create it so that the sound of rain is emphasized. For example the specific design of the external walls and the use of thin paper in the shoji-sliding doors do not isolate against any external sounds. All to create the experience of being in the nature as you sit inside a building.