1. The plaintiff's claim is dismissed.

2. Of the costs of lawsuit, the part resulting from the intervention by the Plaintiff is the Intervenor joining the lawsuit.

1. Basic facts

A. The Defendant was awarded a contract with the Korea Land and Housing Corporation for the construction work of the Seoul Gangnam Complex 1, A3 block apartment (hereinafter “construction work of the instant Section 3”) and the Plaintiff was awarded a subcontract with the Defendant for reinforced concrete construction work among the instant Section 3 construction work (hereinafter “instant construction work”).

B. (1) On December 23, 2011, the Defendant entered into a contract agreement and a subcontract agreement with the Korea Land and Housing Corporation (hereinafter “Korea Land and Housing Corporation”) with respect to the instant three construction sections: (a) on December 30, 2011, the contract amount of KRW 54,249,668,00 for the instant three construction sections; and (b) on February 30, 201 for the date of commencement for the construction period: on February 16, 2012; (c) on August 31, 2013, the date of completion for civil works, machinery, and construction: (d) on August 31, 2013; (b) the Plaintiff and the Defendant entered into the subcontract agreement with each of the instant construction sections by setting the contract amount of KRW 8,086,90,000, and the construction period of KRW 10% from March 31, 2012 to August 31, 2013 (hereinafter “the subcontract”).

The main contents of the instant contract are as follows.

(A) Article 7 (Performance of Contracts and Payment Guarantee of Contract Price) (1) The defendant and the plaintiff shall guarantee each other the execution of contracts and the payment of contract price by any of the following methods:

1. A performance guarantee of the contract amount equivalent to 10% of the contract amount to the defendant. (2) A guarantee between the defendant and the plaintiff under paragraph (1) shall be paid in cash or delivered in a letter of guarantee under any of the following subparagraphs:

1. A letter of guarantee issued by a guarantee agency equivalent thereto, such as a construction mutual aid association, specialized construction mutual aid association, or guarantee insurance company.

Article 14 (Change or Suspension of Construction Works) (1) Defendant.