1. Under Article 6(1) and (2)1 of the former Regulation of Standardized Contracts Act (amended by Act No. 10169, Mar. 22, 2010; hereinafter referred to as the "former Regulation of Standardized Contracts Act"), in order to be deemed null and void on the ground that the standardized contract clause is a clause unfairly unfavorable to a customer, which is contrary to the principle of trust and good faith, the standardized contract clause is somewhat unfavorable to the customer. It is insufficient to say that the standardized contract clause is somewhat unfavorable to the customer. It is not sufficient that the standardized contract contractor abused his position in the transaction, thereby impairing the sound trade order by preparing and using the standardized contract clause against the other party's legitimate interest and reasonable expectation against the principle of trust and good faith. In addition, whether the standardized contract clause is "unfairly unfavorable to the customer" should be determined by taking into account all the circumstances such as the content and probability of disadvantage that may arise to the customer pursuant to the standardized contract clause, impact on the parties in the transaction process, influence on the parties, and relevant provisions (see, e.g., Supreme Court Order No. 201634Da164.

If the terms and conditions are generally and commonly used for a transaction, and the customer could have sufficiently predicted without a separate explanation, or if it is merely a mere degree of refusing or delaying what has already been prescribed by the laws and regulations, it cannot be said that the business entity has an obligation to explain and explain such matters (see, e.g., Supreme Court Decision 2006Da87453, Apr. 27, 2007).

2. In light of the following circumstances, the court below determined that the sales contract of this case where Article 5 (1) of the sales contract of this case, which provides for the settlement of rental deposit in accordance with the rent size of the store allocated after drawing lots, has lost fairness in violation of the principle of good faith, or has violated the duty to explain important contents of the terms and conditions to the defendant, who is the customer, so the above provision is null and void pursuant to the former Terms and Conditions Regulation Act, and thus the above provision should be revised to be applied only within the scope of the increase or decrease of the public area in proportion to the increase or decrease of the exclusive use area.

① Article 10(1) of the Act on the Ownership and Management of Aggregate Buildings (hereinafter referred to as the "Act on the Ownership and Management of Aggregate Buildings") provides that "the common use area belongs to the co-ownership of all sectional owners," and Article 12(1) provides that "each co-owner's share belongs to the ratio of the area of his/her exclusive ownership." Since the common use area of a divided store is usual transaction practice, it would conform to the ratio of the area of his/her exclusive ownership, the increase and decrease of the common use area would be expected to take place in proportion to the increase and decrease of the area for exclusive use if average and reasonable customers are in accord with the ratio of the area for exclusive use. On the contrary, it is extremely exceptional that

② Since the instant sales contract does not provide for the criteria or method of calculating the leased area, if the language and text of the contract clause is interpreted as it is, it may cause unreasonable results contrary to the legitimate interests of the buyer and reasonable expectations by adjusting the rental deposit based on the “sale area plus an area that is not proportional to the increase and decrease of the exclusive use area that can be unilaterally determined after the contract by the business operator.”

③ Article 5(1) of the instant sales contract gives a business owner the right to unilaterally set standards for settlement after entering into a contract, so it is difficult for the purchaser to be unfairly disadvantaged in light of all relevant circumstances, such as the type of transaction of the contract, and it constitutes “a case where the seller grants a business owner the right to unilaterally determine or change the details of the payment without reasonable grounds” prescribed by Article 10 subparag. 1 of the former Act.

④ The Plaintiff did not comply with the purport of statutes, such as the Act on the Ownership and Management of Aggregate Buildings, and the principle of allocation of the common area according to the ordinary practices, and applied unilaterally separate standards established without the consent of the purchaser, and applied them to the separate standards, and filed a claim for settlement based thereon. In the process, the Defendant et al. did not clearly state

3. Review of the reasoning of the lower judgment and the evidence duly admitted by the lower court reveals the following facts.

(1) The E-building project partnership promoted a new commercial building called 'F' (hereinafter referred to as the 'instant commercial building') by implementing a market reconstruction project within the G-dong zone in Seoul, Jung-gu, Seoul, where the land of the old B market was located. On September 2002, the Plaintiff entered into a general execution contract for the reconstruction project with the above reconstruction association.

② On September 28, 2006, the said reconstruction association opened an extraordinary general meeting of its members and made a resolution to include 1/2 of the passage area (so-called "sloping area") linked to each store in the common area of the relevant store when calculating the sale area, and to calculate the remaining common area in proportion to the exclusive area of the relevant store.

③ On July 23, 2007, the Plaintiff entered into the instant sales contract with the Defendant to sell the right of lease on the instant store.

④ Article 1(1) of the instant sales contract provides that “The specific location of a store shall be drawn after payment of the balance, and the sales price shall be settled according to the size of the store determined by lot.” Article 4(1) of the instant sales contract provides that “If there is an increase or a decrease in the area for exclusive use after the drawing of a store, the sales price shall be adjusted in proportion to the increase or decrease rate,” and Article 5(1) provides that “The buyer shall settle the rental deposit according to the rent size of the store allocated after drawing.”

4. Examining the above facts in light of the legal principles as seen earlier, the judgment of the court below is not acceptable for the following reasons.

① Under the Aggregate Buildings Act, common areas, excluding partial common areas, belong to the co-ownership of all sectional owners (Article 10(1)), and each co-owner’s share is in accordance with his/her ratio of the area of his/her section of exclusive ownership (Article 12(1)), but such matters may be separately determined by regulations (Article 10(2)). In actual transactional relations, if each co-owner’s share in common areas is not in proportion to the area of his/her section of exclusive ownership accurately, it is unreasonable

(2) In the case of large-scale commercial buildings occupied by a large number of sectioned stores, the value of each individual store may vary substantially on the same floor. Therefore, it cannot be deemed that reflecting the passage area abutting on the relevant store in calculating the common area that serves as the basis for rental deposit goes against the legitimate interests of buyers and reasonable expectations.

③ In the case of the instant shopping mall, 1/2 of the passage area abutting on each sectional store in calculating the sale area shall be included in the official use area of the relevant store, and the remaining public use area shall be calculated in proportion to the exclusive use area of the relevant store is not unilaterally determined for one of the interests of the relevant project operators, etc., as matters determined through an extraordinary general meeting in order for the reconstruction association members, who were in the position to be determined the location of their own store through the future lottery, to eliminate unfair treatment that may arise among them. This is also revealed in light of the above calculation method, not only the increase in the sale price but also the increase in the sale price but also the increase in

④ In light of the language, content, system, etc. of Article 5(1) of the instant sales contract, it is evident that the rental deposit out of the sales price ought to be settled according to the leased area plus the area for exclusive use by its occupant. In addition, the aforementioned contents are general and common in transactions, and thus, the Defendant also knew or could have anticipated such contents.

⑤ Even if the Plaintiff did not explain to the Defendant that the calculation method of the common area as referred to in the above provision, i.e., 1/2 of the passage area abutting on each of the sectioned stores, and that the remaining common area is calculated in proportion to its exclusive use area, it would have been an important concern for the contracting parties to the instant sales contract or the instant sales contract or the instant sales contract, and the Defendant was notified of the final details of the sales price by the Plaintiff, as well as any objection thereto, even if the Defendant was well aware of, or was well aware of, the above contents from the time of the contract, it would have not affected the conclusion of the contract.

5. Nevertheless, the lower court determined that, solely on the grounds as indicated in its reasoning, Article 5(1) of the instant sales contract is null and void in light of the purport of the former Standardized Contract Regulation Act, and thus, it should be interpreted that the security deposit in the instant sales contract should be computed at an increase and decrease rate of exclusive use area. In so doing, it erred by misapprehending the legal doctrine on the former Standardized Contract Regulation Act, thereby affecting the conclusion of the judgment.

6. Therefore, without further proceeding to decide on the remaining grounds of appeal, the lower judgment is reversed, and the case is remanded to the lower court for further proceedings consistent with this Opinion. It is so decided as per Disposition by the assent of all participating Justices on the bench.

Justices Kim Jae-tae

Justices Park Sang-ok