工程案件情事變更原則之法律與經濟分析

工程案件具有工期長、總價高、規模大的特性，承商與業主間往往因物價波動、地質差異衍生額外費用而產生爭議，倘依原契約條文履行，則恐有顯失公平之情形。我國雖於民法第227條之2 規定情事變更原則，惟司法實務相關之訟爭案件數量眾多，本研究透過採擇有關地下管線遷移、地質差異、物價調整實務判決進行解析，並參考國內法令、相關碩博士論文、座談會研究報告等文獻及資料，提出對於情事變更案件，當事人訴訟上主張之建議，最後再從經濟角度進行分析。針對地質條件引發之情事變更案件，建議先行架構情事變更之事實，即提出締約時兩造認知的地質情形，比較實際履約時的地質現況，地質現況可援引執行契約階段之照片、監造單位意見或訴訟囑託鑑定之鑑定報告。工法若有變更，是否為必需性變更，此部分可援引期刊、文獻等技術資料作補充，或訴訟上鑑定時一併函詢。工期的影響可與原契約工期作比較，成本之影響除考量因數量而增加成本的情形外，也應考量是否因延長工期期間物價劇烈波動導致成本飆升之情形，並以實際支出之費用與契約原編列之價金進行比較。至於是否屬非當事人所得預料，此部分應援引鑽探報告之內容進行頗析，敘明是否仍有其他探查預見地質差異之方式，倘承商無自行進行地質鑽探，則應說明是否有客觀無法鑽探之理由。最後針對情事變更應如何調合，法院則有相當之裁量空間，承商可從成本增加、虧損情形、對於承商之衝擊、風險分配以及經濟效用極大化進行分析。針對物價調整之情事變更案件，可彙總各項指數之變動，例如總指數、中分類項目指數、個別項目指數及各單項實際支出成本之波動、該時期其他相同類型標案相同工項單價預算編列之情形，均可作為客觀市場行情波動之佐證，並說明物價波動屬非常態性波動之理由。另提出承商實際額外支出之成本，參酌因工程預期所能獲得之利益，請求法院酌定適當之分攤。

關鍵字

情事變更原則；民法第227條之2 ；地質差異；物價波動

並列摘要

The characteristics of Engineering cases are long duration, high total price and large scales, and there is often controversy between contractors and owners over additional costs arising from price fluctuations and geological differences. It may be unfair if the contract is performed in accordance with the original provisions. Although the law of our country has the principle of Clausula rebus sic stantibus, the number of cases is numerous. This study focuses on the analysis of underground pipeline migration, geological differences, price adjustment practice decisions, and reference to R.O.C laws and regulations, master dissertation and doctoral dissertation, researches and references. The proposition of making suggestions to the parties in the litigation lies Clausula rebus sic stantibus, and finally analyze it from an economic point of view. In view of the cases caused by geological conditions, it is suggested that the geological situation recognized by both parties at the time of contracting need to be put forward first, comparing the geological status at the time of actual performance, and the geological status can be referred to the photos of the execution stage of the contract, the opinions of the supervision unit or the appraisal report of the lawsuit entrust appraisal. If there is a change in the construction method, whether it is a necessary change or not, this part can be supplemented by citing journals, literature and other technical data, or the letter of inquiry when appraising in litigation. The influence of the construction period can be compared with the original contract. The impact of cost should be considered not only because of the increase in quantity, but also because of the sharp fluctuation of prices during the extension period, and compared with the actual cost of the contract. This section shall be analyzed with reference to the drilling report as to whether there are other ways of examining geological differences and, if the contractor did not conduct his own inspection, whether there are reasons for his objective inability to conduct his own inspection. Finally, the court has considerable discretion on how to adjust the change of circumstances, and the contractor can analyze the cost increase, loss situation, impact on the contractor, risk distribution and economic utility maximization. In the case of price adjustment, the changes of various indices, such as the fluctuation of the total index, the index of classified items, the index of individual items and the actual cost of expenditure of each individual item, and the situation of the same work unit price budget of other similar types of tenders in this period, can be used as evidence of objective market fluctuations, and the reasons why price fluctuations are not normal fluctuations. The cost of the contractor's actual additional expenditure is also proposed, taking into account the benefits expected to be obtained from the work, and the court is requested to determine the appropriate allocation.