Japan Dome House, a modular home manufacturer, has been making and selling its styrofoam dome houses for over fifteen years, but since the April 2016 Kumamoto earthquakes, there has been a surge of interest in the company’s products.
Some readers may do a double take, as the material used for these homes is indeed styrofoam.
Polystyrene (more commonly known as styrofoam) is widely used for everything from cups and food containers to packaging material. Polystyrene is a petroleum-based product made from the styrene monomer, which is classified as a possible human carcinogen by the Environmental Protection Agency (EPA) and by the International Agency for Research on Cancer (IARC).
Some countries and municipalities around the world (including Taiwan and Portland, Oregon and Orange County, California in the U.S.) have also banned the use of polystyrene foam.
Nevertheless, the future of earthquake-resistant home building in Japan may very well come in the shape of domed houses built from this material.
Aso Farm Land
On April 16, 2016, a magnitude 7.0 main shock struck the city of Kumamoto in Kyushu Prefecture (following a foreshock two days earlier). The two earthquakes killed at least 49 people and injured some 3,000 others.
Many structures in Kumamoto and Oita Prefectures collapsed and caught fire, and more than 44,000 people were evacuated from their homes due to the disaster. Thousands of evacuees are still living in temporary housing.
However, among the structures that were not damaged was a small village of 480 houses at the Aso Farm Land resort, a health-themed national park built on a somma volcano, in Kyushu. Visitors to Aso Farm Land can enjoy numerous open-air hot springs and stay overnight in differently-themed accommodations.
The “Village Zone” of Aso Farm Land consists of 480 closely-packed dome-shaped houses made of a next-generation form of polystyrene foam. When the Kumamoto earthquake struck, none of these dome houses were damaged. This has has lead to a surge of interest in the technology behind their construction.
Fourth-Generation Building Material
Japan Dome House, based in Kaga City, Ishikawa Prefecture, claims that it has developed a fourth generation building material (following wood, iron, and concrete); and that its dome house has a number of characteristics that makes it superior to conventional materials and house shapes.
Using proprietary technology, it has developed an expanded polystyrene (EPS) product that is much stronger and more compact than the foam that is used for shipping material and food containers.
The company believes that its dome houses have a number of benefits. These include:
Ultra-Short Building Time
A dome house can be assembled in about a week by three or people, using modular dome pieces that weigh only about 80-kg (176 pounds).
The company says that the total construction cost of a basic dome house is between ¥7 million and ¥8 million ($68,700 and $78,500) for a house with a floor space of about 36-sqm (387-sqft) and a ceiling height of 3 meters (9.8 feet).
Highly Earthquake Resistant
Because of its dome shape, the lack of a need for posts and beams in construction, and its extremely light weight the dome house is highly earthquake resistant.
Expanded polystyrene also has very high thermal insulating properties. This combined with the dome shape (which allows air to circulate by convection and prevents it from accumulating in corners) makes the dome house highly energy-saving.
Polystyrene also does not rust or rot and is not subject to termite infestation. After assembly, the walls of the Dome House are also coated with fire retardant making the houses fireproof.
The dome shape of the house also makes it resistant to high winds.
Antioxidant Building Construction
The company also claims that its houses are healthy to live in because an anti-oxidant solution is kneaded into the polystyrene foam building material. Formaldehyde is also not used in the construction process which means that Japan Dome Houses do not suffer from “sick-house” syndrome.
The Dome House and the company’s specially developed polystyrene foam have also been certified by the Ministry of Land, Infrastructure, Tourism and Industry as being compliant with national building codes.
Customizable Dome Houses
Japan Dome House has developed a number of modular parts for its dome houses, which makes them highly customizable.
The company says its dome houses are used around Japan not only as residences but also as small hotels, steam rooms, temples and churches, child care centers and educational facilities and even karaoke bars. Because they can be quickly assembled there is also growing interest in using them as temporary housing for evacuees from natural disasters.