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From scrap to sustainable living: Japan's first 'earthship' to open doors as guesthouse

Earthship Mima, with its unique appearance, is seen in the Tokushima Prefecture city of Mima in January 2020. (Mainichi/Ayane Matsuyama)

TOKUSHIMA -- Japan's first "earthship" -- a structure built with recycled materials that supplies its own water and electricity -- has been constructed in western Japan from materials including 800 old tires, 4,000 bottles and 13,000 empty cans.

The structure in Mima, Tokushima Prefecture, dubbed "Earthship MIMA," will open as a guesthouse in May. Tomoko Kurashina, 46, from the eastern Japan Prefecture of Kanagawa who played the leading role in the facility's construction, says she hopes it will spark ideas for creating a sustainable society.

It was after the March 2011 Great East Japan Earthquake and tsunami and the ensuing meltdowns at the Fukushima Daiichi Nuclear Power Station in northeast Japan that Kurashina began to think about issues relating to energy and the environment.

Tomoko Kurashina explains a system to purify rainwater in the newly built earthship in Mima, Tokushima Prefecture, on Jan. 14, 2020. (Mainichi/Ayane Matsuyama)

"The accident occurred because this isn't something that we are able to control completely at this stage," Kurashina recalls thinking. She tried living without electricity for about a month afterwards. When she started using it again, she realized how good it was to have it, and decided that she would not refuse a life without it. Still, she began thinking that she wanted to live in a home that maintained the conveniences of electricity, while having a low impact on the environment.

It was around this time that she found out about the earthships pioneered by American architect Michael Reynolds. Kurashina had wanted to live in a naturally rich environment and so in 2015 she applied to join a team the city of Mima was forming to boost the development of the area. She moved from her home in the Kanagawa Prefecture town of Hayama to Mima and decided to build her own earthship.

Kurashina raised part of the 40 million yen it cost to build the home through crowdfunding, and when she contacted Reynolds, he came to all the way to Japan to provide advice on the project. Construction began in 2018, and the 100-square-meter home was completed in the summer of 2019. It includes two bedrooms, a kitchen, and a bath and toilet.

Empty cans are built into a wall of the earthship, serving as an insulation material, while cutting down the amount of mortar required, in Mima, Tokushima Prefecture, in this photo provided by Tomoko Kurashina.

The 800 old tires collected to build the home were inserted into the walls, serving to provide insulation and store heat. Placing empty cans between layers of concrete also provided insulation and meant that less mortar was needed.

There are no heating or air conditioning appliances in the home, but the temperature inside is said to stay at around 21 degrees Celsius throughout the year.

The thousands of empty bottles were used to let light into the home with a stylish appearance, somewhat like stained glass. Solar panels were placed on the roof and the surplus energy is collected in storage batteries.

Old tires filled with soil are used in the construction of the earthship in Mima, Tokushima Prefecture in this photo provided by Tomoko Kurashina.

The home's water supply comes from rain, which gathers in a 6,000-liter tank and passes through a filtering device that can remove 99.9 percent of the bacteria in it. Some of the discharged water is delivered to planters on the premises, avoiding waste.

While it is not possible to use hair dryers and other appliances that consume a lot of electricity, the earthship apparently offers a comfortable living environment like that of a regular home.

After the home was completed, architects and experts with an interest in environmental issues who heard about the nation's "first earthship" have flocked to inspect it. It will be rented out as a guesthouse from May, being able to accommodate up to five people.

The interior of the newly built earthship in Mima, Tokushima Prefecture, is seen on Jan. 14, 2020. (Mainichi/Ayane Matsuyama)

"I want people to use the guest house and realize that the hurdle for creating an environmentally friendly home is not that high," Kurashina says.

Inquiries about inspecting the earthship and its use as a guesthouse can be made online through (in Japanese).

(Japanese original by Ayane Matsuyama, Tokushima Bureau)

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