Japan, a nation frequently experiencing seismic activity, has developed an innovative air-lifting technology to protect residential buildings from earthquakes. Air Danshin Systems Inc. is the developer of this system, which isolates houses from ground tremors by elevating them approximately 3 centimeters off their foundations in under a second upon detecting an earthquake. Once seismic activity ceases, the house is lowered back down.
The system includes emergency batteries for functionality during power outages. Nearly 90 buildings in Japan are already equipped with this technology. During a magnitude 7.3 earthquake in February 2021, all 30 houses fitted with the Air Danshin system reportedly remained undamaged. The installation cost is approximately one-third of traditional seismic isolation methods. However, some experts have raised concerns about its performance in extremely powerful or multidirectional earthquakes, and whether its activation speed is sufficient for initial, intense tremors.
Traditional seismic isolation methods in Japan, such as base isolation bearings and damping systems, have been in use for decades. The Air Danshin system is noted for its lower cost and potential for easier retrofitting into existing buildings, which is crucial given that a significant percentage of older Japanese homes require seismic retrofitting. For instance, a 2018 report indicated that approximately 93% of wooden homes inspected in Tokyo needed such upgrades. The Japanese government actively supports seismic retrofitting through tax deductions and subsidies.