Abstract
This work is a modeling system using local resources and 3D printing equipment on a sandy beach.The on-site construction system using local natural materials reduces transportation costs and environmental impact, and realizes sustainable architecture.

Background
My attention was drawn to sustainable architecture and building materials due to my awareness of the large amount of waste created by the scrap-and-build nature of buildings in modern society.
I was also inspired by nature’s beautiful sand formations. I thought that by intervening a little in nature, it would be possible to build from materials available at the site with the aid of natural action.

Details
1. Concept
Sand and water were chosen as the materials and principles to realize the concept of building from materials available at the site with the assistance of natural action.
2. Principle Experiment
Sand and water were prepared and tested by hand to see if it was possible to reproduce the molding process of sand hardening as it becomes wet when rain falls.
3. Experiments
Using the developed device, we verified the parameters of computer control. We also established the modeling procedure and experimented with various shapes.
4. Large-scale CNC development
A large-scale device was developed. The main differences from the small-scale CNC system were the structural burden of the frame and the increase in molding time. We designed the machine to be structurally and transportably rational.
5. On-site production
The production was actually carried out on a sandy beach, and the local manufacturing was verified. It was found that the texture of the sculpture was strongly affected by the weather, such as wind, and that the texture of the sculpture varied greatly depending on the sand grains used as materials.

Conclusion
The first difference from existing manufacturing processes is the use of non-standardized materials as building materials through digital fabrication. The second difference is that local manufacturing is possible only by transporting the equipment. The second is that the equipment can be manufactured locally with only the transportation of materials. This is expected to reduce transportation costs and environmental impact of factory manufacturing and transporting materials to the site. Third, the materials return to their original cycle through natural processes. Since no chemical adhesives are used, the materials will return to their natural state after being dismantled by drying and erosion caused by sunlight and wind. This is suitable for creating temporary spaces on sandy beaches. The building, which is constructed in isolation from the natural environment, is positioned in the circulation as a stagnant part of the natural flow.