Brown notes that in the early 17th and mid-19th centuries, Japan faced many of the same problems we face today, like scarce resources for a large population. Through his studies with traditional carpenters, he learned a few lessons about how Edo-era Japanese used design to address these problems.
"One of the most important lessons is that the primary design response to material and energy shortages of the era was to seek multiform solutions, designs that solved many problems at once. We see this in the easy convertibility of the traditional Japanese interior, which allows rooms to be used for a variety of purposes. But the same attitude led to the development of rice paddy irrigation systems, which were almost entirely gravity-fed, acted as cascading filters for the water supply, and could function as solar-heated warm-water tanks for processing hemp and other plant-based textile fibers."