Abstract
Construction contract is generally regarded as a contract for work. Contrary to sales contract, a special feature of construction contract is to make the object according to Owner's direction and/or material. Various problems may occur and effect construction period during construction process. To treat the problems after a conclusion of the contract, Contract period prolongation clause was introduced and has been revised in the General Conditions of Government Construction Contract. But, there has been pointed out that the reality of in situ situation is not properly reflected in this clause. Therefore, the problems of the prolongation clause was analysed. And the role of contract parties and the new prolongation process was suggested in this study.