원인불명의 화재로 임차 외 건물 부분에 발생한 손해에 대한 임차인의 채무불이행책임- 대법원 2017. 5. 18. 선고 2012다86895(본소)‧2012다86901(반소) 판결 -

According to the past cases of the Korean Supreme Court, unless a lessee proved that he had taken measures to keep leased premises with due care of a prudent manager, he was liable for damages to leased premises burned by the cause of the fire and its origin, which is unknown. In addition, the lessee was liable for damages to unleased premises, which is inseparable from leased part of the building in the maintenance and existence of the building. The expansion of the range of damages ignored the characteristics of the fire and made the status of the lessee poor. And, it is impossible for lessee to prove to fulfill such due care to keep leased premises. Thus, many scholars and commentators criticized the decision as unfair. The recent Korean Supreme Court en banc Decision, May 18, 2017, 2012Da86895, 86901 ruled that, the lessee is liable to compensate the lessor for ‘contractual damages’ to the unleased premises from the fire of unknown cause in the leased premises owned by lessor (lessee’s contractual liability), if the following conditions are met: if a contractual breach on the part of a lessee, such as providing the cause of a fire by failing to preserve and manage the leased object, has been proven; and if there is reasonable causation between the contractual breach and the damages incurred to the unleased premises. I think that this ruling is quite reasonable and fair, because the lessee is held liable for default by separating leased premises and unleased premises. This also complies with the requirements for the formation of a liability for default and the principle of burden of liability for proof. In the future, it will be very important in the practice of legalizing claims by dividing the damages caused by leased premises and unleased premises.