By Kyle Holzhueter
Editors Note: Continuing his series on natural building in Asia, Kyle explores the current state of bale construction in Japan. Future articles in this series will include a focus on Thailand and more from Japan. There are 50 images in this article, so make sure to click on them to see more detail.
There are 8 pages in this article. Please navigate using the pages buttons at the bottom of each page.
Rice cultivation is common throughout most of Japan. Subsequently, rice straw is locally and plentifully available. Historically, rice straw was a valuable commodity in pre-industrial Japan. Rice straw was used in agricultural and architectural applications and was also used in the production of daily goods. For example, rice straw provided bedding for livestock, thatch roofing for buildings, and flooring for homes in the form of tatami mats. In pre-industrial Japan, rice straw was also used to create sandals, snow boots, raincoats and other commonly used items. Although rice straw is still used for various applications, in modern mechanized farming, at the time of harvest, the combine chops grain straw into 15cm (roughly 6in) lengths and returns the chopped straw to the soil. But rather than discuss the traditional uses of rice straw in Japan, this article hopes to explore the relatively recent use of straw in Japanese architecture, namely straw bale building.
Each country presents a unique architectural context, including climate, cultural norms and architectural history. We’d like to explore straw bale building within Japan’s unique architectural context. For example, Japan is one of the most seismically active regions in the world. Also, compared to Europe, North America and Australia, Japan’s climate is characterized by high humidity and precipitation. Traditionally, homes consist of a timber frame on pier foundations with non-load bearing walls. And culturally, shoes are removed at the front door and living quarters have raised floors. Lastly, since exhaust from fires for cooking and heating directly entered the living quarters in traditional homes, there was never strong emphasizes on building air tightness or thermal insulation. Modern straw building in Japan finds itself within this climatic, cultural and historical context. Here we describe how straw bale building in Japan has developed from and adapted to this context.
Today, in Japan and throughout the world, awareness of environmental problems continues to rise. As a response, interest in natural and alternative building, such as straw bale building, also continues to grow. The actual number of straw bale buildings in Japan increases every year.
Although there are some load-bearing straw bale structures in Japan, most straw bale homes are non-load bearing, meaning that loads are carried by a frame, generally timber, and straw bales are used as an infill.
The greatest challenges facing straw building in Japan are damage from moisture and the susceptibility of straw to microbial decay. These challenges will be discussed in greater detail in a subsequent article. The purpose of this first installment is to photographically present the variation of straw building in Japan.
According to the International Straw Bale Building Registry, as of February 2014, there are over 1625 straw bale buildings in 50 countries on six continents. However, only three buildings are listed for Japan, whereas the author has identified over 50 straw bale buildings in Japan. The International Straw Bale Building Registry recognizes that the registry does not reflect the actual number of straw bale buildings in the world and that the global number of straw bale buildings is actually much larger. And since the registry is conducted in English, non-English speaking countries are naturally under-represented.