A. On March 10, 1993, the Defendant is a land partition rearrangement association established for a land readjustment project (hereinafter “instant rearrangement project”).

The plaintiff is a regional housing association established for the purpose of constructing a new apartment house in three lots outside the Dor of the B-Land Partitioning Zone, which is a land allotted by the authorities in recompense of development outlay located in the project district of the instant rearrangement project.

B. Around March 2015, prior to the completion of the instant rearrangement project, the Plaintiff filed an application with the Ulsan Metropolitan City Mayor for approval of the housing construction project plan for constructing an apartment housing with a scale of 520 households on the ground of the said land. In this regard, the Defendant submitted to the Ulsan Metropolitan City Mayor on August 31, 2015, a letter of commitment to the alteration of urban planning (road type), construction of roads for G, E, F, I, J, and H, and the letter of commitment to the alteration of urban planning (hereinafter “instant letter”), construction of roads for G, E, F, I, H, and H, to the extent that the urban planning implementation plan was modified as a lawsuit until December 31, 2015, and expansion of the width of H roads by a lawsuit, and submission of the letter of commitment to the alteration of urban planning (road type), road construction, road construction, and donation commitment (hereinafter “instant letter”).

C. On the other hand, the Plaintiff submitted to the Ulsan Metropolitan City Mayor a performance assurance (hereinafter “instant performance assurance”) promising the Plaintiff’s performance if the Defendant failed to complete the alteration of urban planning (road type), construction of roads, or donation acceptance as agreed by the instant letter of undertaking due to unavoidable reasons.

On September 18, 2015, the Ulsan Metropolitan City Mayor approved the housing construction project plan (hereinafter “instant project approval”) from September 2015 to October 2017 by setting the project period to the Plaintiff from September 18, 2015, and the following approval conditions (hereinafter “instant approval conditions”) are added thereto:

30.Housing Construction Project Site.