The costs of appeal shall be assessed against the defendants.

1. As to the interpretation of the contract:

The facts duly established by the court below are as follows.

The Defendants transferred 319 square meters on September 21, 1979 between the Defendants and the Namdo Co., Ltd. (hereinafter Nonparty Co., Ltd.) as a site for new building, and the Defendants Co., Ltd. constructed 1,940,000 won for total construction cost in accordance with the construction permit obtained from Gwangju City. The ownership of this Center belongs to the Defendants. The Defendants shall use the remaining portion of the Corporation without compensation for 15 years from the completion date of construction, and if the non-party Co., Ltd. fails to complete the completion date of construction within 45 days from the date of construction permit of the Center, the above loan period may be reduced to the extent of delay for the Defendants Co., Ltd. to the extent that the non-party Co., Ltd. did not arbitrarily cancel this contract, and the non-party Co., Ltd., Ltd.’s right to request the return of unjust enrichment to the 197th anniversary of construction cost of the construction permit of the 15th anniversary of the total construction cost of the 197th anniversary of the construction permit.

As seen above, according to the terms and conditions of the contract between the Defendants and the non-party company, the non-party company established the center of this case at its own expense to vest in the Defendants, and instead, the non-party company agreed to use the remainder except for part to be used by the Defendants for 15 years after the completion of the contract without compensation. Thus, this free use can be seen as substituted for the above construction contract. However, considering the contents of the above special contract, when the construction work of the non-party company was ceased intentionally, not in extenuating circumstances such as natural disasters, the Defendants can arbitrarily cancel the contract, and the non-party company cannot claim any construction cost invested in the construction work until then, and in light of the purport of the special contract, the non-party company cannot claim any compensation and any right of free use. Since the non-party company could not recover the investment cost from the beginning of the contract, the purport of the above special contract clause is no more meaningful.

On this basis, considering the above special agreement clause, it is necessary to interpret it strictly because it is a clause that is remarkably unfavorable to the non-party company, and Article 18 of the contract of this case (Evidence A11) of this case is deemed to be in accordance with the ordinary social norms, and it should be comprehensively interpreted in a combined manner to the effect that the contract of this case is "faith which is not an inevitable cause, such as a natural disaster," as stated in the special agreement clause of this case.

Therefore, the court below is justified in holding that the discontinuance of construction by the non-party company does not fall under the case where the non-party company intentionally suspended construction because the non-party company intentionally did not include not only intentional acts but also the case where the construction was interrupted due to the reasons attributable to the non-party company's fault, such as the Gwangju situation in 1979, 190.5. The reason is that the non-party company's discontinuance of construction was erroneous or incomplete trial or the judgment was erroneous.

2. As to the cancellation and effect of the contract:

The judgment of the court below does not intentionally suspend construction work, and thus, the defendants cannot cancel the contract pursuant to the above special agreement clause, but can exercise the right of statutory rescission on the ground of the non-party company's delay. On this premise, the defendants are liable to settle and pay the costs invested by the company to the non-party company, and the amount to be returned to the non-party company is calculated

According to the records, the defendants asserted that the declaration of the cancellation of the contract to the non-party company is the exercise of the right to cancel the contract reserved in the special agreement clause, but the plaintiff also assumes that the contract is terminated due to the defendants' declaration of the cancellation of the contract. However, the plaintiff argues that the notice of the cancellation of the contract under the special agreement is invalid, and that the defendants' declaration of the cancellation of the contract is to extinguish the validity of the contract on the grounds of the non-party company's cause attributable to the non-party company. In addition, the defendants' notification of the cancellation of the contract satisfies the requirements of the notification of the cancellation of the contract due to delay of performance.

Therefore, the general principle of termination of a contract is that the contract becomes retroactively terminated, and the contractor is entitled to claim remuneration for the contract, but in the case of the contract for construction, even if there is a completed portion, if the construction is considerably advanced, and the restoration to its original state would incur serious social and economic loss, and the completed part would benefit the contractor, the above should be dealt with differently. In other words, if the contractor cancels the contract for construction on the ground of the contractor's default, it should be deemed that the contract is invalidated only for the un completed portion. This is so in light of the purport of the proviso of Article 668 of the Civil Act, which denies the contractor's right to rescission for a building or other structure of land, or in light of the good faith principle.

Therefore, in this case, the contractor is obligated to deliver the building to the contractor as it is at the time of cancellation, and the contractor is obligated to pay the reasonable remuneration for the transferred building in consideration of the completion of the building.

In this case, according to the court below's determination, the non-party company, the contractor, carried out construction of this case's hall at least 90 percent, and the defendants are currently taking possession and use of the above hall, so the defendants are obligated to pay the non-party company remuneration equivalent to the weather. Furthermore, on the premise that the non-party company has a claim of KRW 1,472,448,486, which was invested in the construction of the above hall by the non-party company based on its adopted evidence, the court below is justified in the judgment below which partially accepted the plaintiff's claim, on the ground that the lease contract entered into between the non-party company and the non-party company was renewed by a lease agreement between the non-party company and the third party, including the lease deposit received, and the balance of the non-party company's advertisement fees, electricity fees, and taxes paid or guaranteed by the defendants exceeds the claim amount of this case's claim that the non-party company transferred to the plaintiff. It is without merit

Therefore, the appeal is dismissed, and the costs of appeal are assessed against the Defendants. It is so decided as per Disposition by the assent of all participating Justices.

Justices Park Jong-soo (Presiding Justice)