Brunat in turn hired Edmond Auguste Bastan to create a blueprint for the design of the silk mill, which was completed the end of December 1870. Bastan was able to complete the design such a short period as he had previously designed the Yokosuka ironworks and was familiar with made of timber-framed brick buildings. Brunat returned to France on to purchase equipment and hire engineers. In the interim, Odaka Atsutada was placed in charge of the Japanese side and started procuring materials, and in March 1871, construction started. Brick was not yet in common use, so a brick kiln had to be constructed in what is now Kanra, Gunma where clay of the appropriate quality had been found.
