Chapter 4: Housing ○Residential Basic Materials [1]

 Many Japanese homes lack insulation, causing heat to escape during winter despite continuous heating efforts and leading to condensation on windows. Continuing heating in this state becomes an unnecessary waste of electricity. To combat this, insulation materials are used to prevent heat from escaping. Additionally, incorporating double-glazed windows and 24-hour mechanical ventilation allows for the use of heating and cooling systems year-round while minimizing electricity consumption.

    Moreover, concrete used in buildings, apartments, and residences emits a significant amount of carbon dioxide during its production process, contributing significantly to global warming. It's essential to reduce its usage in light of these issues.

    Considering these problems along with the immediate need to address housing inadequacies, poverty, refugee concerns, it's possible to start constructing houses now that are sustainable worldwide. Regarding the basic materials, these include bamboo (wood), straw, soil, clay, stone, lime, and water.

    Straw is dried stems of plants like rice and wheat. Rice is cultivated across Asia, from Japan to India, while wheat is grown worldwide in Africa, Europe, Asia, Russia, Australia, Canada, Argentina, among other regions. Consequently, straw is widely available, and it's bundled into blocks approximately 50cm wide to serve as insulation. These blocks are stacked between the columns of a dwelling. The interior and exterior of these straw walls are covered with mud to create earthen walls. Such houses are known as "straw bale houses," and bales are created using an agricultural machine called a baler, which compresses dried grass or straw into block shapes.

    Additionally, methods of construction such as "cob" and "adobe" involve mixing water with materials like sand, clay, and straw to create earth or brick walls. These architectural methods have been observed across various continents since ancient times. Adding fibrous materials like straw helps elongate and bind the soil, increasing the tensile strength of cob.

    As these earth walls are susceptible to weakening when exposed to the elements, they are further coated with materials like lime plaster mixed with oil on the exterior to enhance waterproofing and durability.