Armed with basic tools and an approach intentionally free from rigid blueprints, Oka began working on it in 2005. Over the next twenty years, he shaped, added to, corrected and rewrote his building by hand, effectively creating a three-dimensional construction diary. The architect built the Arimaston through a radical process of total self-construction, involving the manual mixing and carrying of raw materials such as concrete, step by step, without the use of heavy machinery.