Report on Kajima Construction Site

On November 21, 2019, we, the 2019 Raccoons, gathered at the station in Tokyo at 14:30 amidst the warm afternoon sunlight which seemed to ward off the winter cold of the day before. From there, we went to the construction site which Kajima designed and constructed.

This building complex stands at 89.9m (highest point 99.9m), and has 25 floors above ground and 1 basement floor below ground. The total floor area is 34,800m2. The first and second floor consists of shops, a daycare center and community services. On the second to fourth floors, there are 49 apartments with facilities for the elderly. There are 229 rental apartments located on the 5th to 25th floors.

Together with the chairman of the board and the staff members of SGRA, we were first given an orientation by the project site manager. Then, we visited a room still under construction and another room which had already been completed. We ended our visit with a question and answer session and by sharing our impressions.

+ Craftsmanship "minute" and "gigantic" precision from 1m/m

General contractors in Japan have abilities of which Japan can boast about to the world.
We had the precious opportunity to experience such craftsmanship at the Kajima site.
Most impressive for all of the Raccoons was Kajima's pursuit of the limits of technology.

The project site manager showed us a slide of a 50 years old building which has outer walls and metal-framed glass windows. We could see moss on the outer walls, but the sealing for the metal-framed glass between sash and wall were kept clean and was not deformed despite being 50 years old. We felt the strong will and determination which sought after perfect waterproofing for concrete and aluminum sash. He talked enthusiastically about sealing technology, which can be overlooked easily but which shows their technology and strong will which can be kept for a hundred years.

When we went to a room under construction, we made another discovery. It goes without saying for waterproofing, but measures for soundproofing have also been considered perfectly. Kajima designed integrated piping for the floors and ceiling and multiple measures for soundproofing. We were very lucky in that we could see the structures under the floors which were dozens of centimeters thick. Normally it would not be possible to see this after the completion of building.

After changing into slippers we entered another room which Kajima had already completed work on. The interior of the room was beautifully covered with partitioning walls which also served to soundproof the room and a simple predominantly white and grey interior. In this room, we could see the "1m/m" proofing layers which absorb shock between the walls and floors perfectly. The rubber layers are set just a few millimeters behind the wall and cannot be seen from the outside. If we dare to insert our fingers into the crevices, we may be able to touch or feel their existence from their subtle repercussions. Besides those layers, there are other sound proofing devices that allow one to enjoy a living space free from the interference of sounds.

It is this minute "1m/m" that makes all the difference. We cannot see it even if we set our faces closely to the floor. We can feel it, only if we touch it with our fingers. However, this "1m/m" is a crystallization of the spirit of craftsmanship to attain a goal, and supports "gigantic" general contractors. It symbolizes their dreams as well as the dreams of all human beings.
This is the craftsmanship of Kajima - the ability to build and support and switch between the "minute" and "gigantic"?

+ From "Ma" and "Kasanari" to "One" - Skillful in "Building"

To build is not always to persevere on one's own. It is said that business by general contractors is established through the collaboration of industry specialists. In other words, it is the general contractor who builds "one thing" through expediting collaboration between specialists with a specific framework in mind.

According to the project site manager, about 100 companies (and over 300 engineers) are involved in this project. For example, in designing the garden, actors for landscape, lighting and soft scape are involved. Furthermore, each design needs to be unified with the whole project and in harmony with the facade by Kengo Kuma, the designer of this project.
A whole system, in terms of not just technicality but also system management, is necessary. How can one analyze the project or make use of specialized technologies?
How can subsystems be adjusted and projects compiled smoothly? This is the specialized know-how of Japanese contractors who have registered architects with a first-class license and the management know-how of Kajima that can answer such questions.
In order to create a singular project "the one" it is necessary to have "the craftsmanship" to link each analysis completely together.

+ For the renovation of town

This project is the renovation of a housing project to transform the estate into a high-rise consolidated building. Various services such as rental housing, nursery schools, homes for the elderly and an open green space are prepared. It is not an urbanization project to build a new building. The project in Aoyama will without doubt become a model for the renovation of community and public spaces.

Chen, Zhao (2019 Raccoon)

Translated by Kazuo Kawamura
English checked by Sonja Dale