by Nick Gromicko, CMI®
While Styrofoam™ may be most commonly associated with meat trays and disposable coffee cups, the material is considered by many to be a residential building material.
Communities composed entirely of Styrofoam™ are already a reality in progressively minded Japan. These structures have been approved by Japan’s Land and
Transport Ministry, and, with the proper permit, they can be erected anywhere in that country, where they are known as “dome homes.”
Prefab home manufacturers use the material to construct easy-to-assemble, igloo-shaped modular kit homes. The Aso Farm Land resort village in Kyushu is one notable instance, where 480 Styrofoam™ domes serve as lodging, recreational facilities and retail shops. They are built from 7-inch thick, snap-together wall sections made from a type of Styrofoam™ that is considerably stronger than ordinary packing foam. Dome house kits start at around $30,000, and this price does not include the cost of transport or assembly.
Manufacturers of dome homes boast the following advantages over homes built with wood or metal:
- They do not rust, decay or attract termites. It’s still wise to have an InterNACHI inspector search for such defects.
- They are earthquake-resistant. In fact, models tested by the Federation of American Scientists (FAS) did not merely meet earthquake standards; they remained fully intact after being shaken harder than the strongest earthquakes ever recorded. Styrofoam™ houses can withstand typhoons, too.
- The walls are treated with a flame retardant that emits no toxic fumes during a fire.
- Construction is quick and easy. The prefabricated pieces, which each weigh about 175 pounds, can be carried by two or three people and assembled in a few hours.
- They have excellent thermal-insulation properties, resulting in higher energy efficiency and lower heating and cooling costs. Tests performed by the FAS found that Styrofoam™ can cut heating and cooling costs by 50% to 60%, in some cases.
Even in the United States, where dome homes are still the stuff of hobbits and smurfs, Styrofoam™ homes have passed uniform building code standards, and they represent a growing niche market. In Hawaii, for instance, entire conventional multi-story homes – not Japanese-style dome homes – are being constructed from Styrofoam™. The ceiling, stairs, walls, support beams and roof of such a home are constructed with cement-coated Styrofoam™ and lack straps, tie-downs, nuts and bolts. Even the gutters are cut into the foam, and everything conforms to the building code. According to the manufacturer, these homes are cooler than homes made from conventional building materials, and they cost 10% less to construct.
Another growing market in the United States is homes that are built from a concrete-foam hybrid. The result is a synergy of the insulative capability of Styrofoam™ and the strength of a standard building material. The foam provides continuous insulation, as opposed to traditional insulation that has a break at every wood stud. The technique is about 3% to 5% more expensive for new-home construction.
In summary, Styrofoam™ is emerging as a promising building material for residences.