Tree house

This is a house for young editor's couple in typical residential area of north part of Tokyo.
The site is surrounded by neighbor's houses closely for all directions. It seemed difficult to open the house to horizontally. Normally this site-type is hated for housing for the reason of problem of shortage of natural light and privacy. But we found one unique potential with this dusky site. That is "centripetal tendency" by limitation to horizontally.
So we selected the Polar-coordinate-system as geometry of architecture instead for Cartesian-coordinate-system which is generally used in architectural design. The rule is very simple. Each LVL-frame was rotated and reproduced by 11.25 degrees. And every frame is higher 55mm than next one. As a result, the rational strong structure which looks like big tree has been realized.
The main space is divided to 4 different characterized spaces by this big Tree-like column. All spaces have different composition by height and width and different light amount. So we imaged actions along these characters of spaces. For example, high and well lighted space is for dinning, low and dim cozy space is for sleeping.. In this house people will find his favorite space by himself, not by order from named rooms with functions.
But beyond my many words, this old song express my concept simply and correctly.

"Under the spreading chestnut tree.
There we sit both you and me.
Oh how happy we will be.
Under the spreading chestnut tree."
(UNDER THE SPREADING CHESTNUT TREE)

I wonder that we could realize the space sang by this familiar song in Tokyo.
(Masahiro Harada)

Now I remind that the way to divide the space by symbolic center column is very traditional way in Japan. We can find many old houses by same system. Maybe this is one reason why old grandmothers of neighbor's like this very modern house.
In the way, this geometry succeeded to change the roof to interesting terrain. Normally it is difficult to get comfortable garden in this kind of situation. But there exist sunny and opened terrain on the roof.