The defective construction of residential buildings by major apartment operator Leopalace21 Corp. will force thousands of tenants to vacate their homes due to safety concerns. Both the company and the authorities need to determine why such large-scale faulty construction was allowed to happen and take steps to ensure such problems aren't repeated in the future.

The apartments were reportedly built with ceiling and wall material that didn't meet the specifications of the Building Standards Law, thus compromising the standards for fireproofing and sound insulation. Leopalace21 said 1,324 apartments across Japan — in which 14,443 people now live — are affected. The company is requesting some 7,800 residents of 641 properties that are deemed particularly dangerous in the event of a fire to move out by the end of March, and also plans to urge tenants living in other defective apartments to vacate their units later so the defective construction can be repaired. The moving costs will be shouldered by the apartment operator.

Leopalace21 builds apartments for landowners. It rents out the properties and manages the apartment units — mainly for single occupants — and the landowners are guaranteed a certain level of income. The company currently operates 570,000 apartments nationwide.