本文嘗試重新建構我國違章建築「事實上處分權」之法律地位。首先,從我國實務見解出發,在肯認違章建築係屬不動產且為融通物,惟無法為建物所有權第一次登記及移轉登記之前提下,特別著重於觀察最高法院創設「事實上處分權」之法律概念後,其於民法領域之不同案件類型中所採之見解,嘗試歸納出「事實上處分權」法律地位之整體圖像,並與所有權之權能相互對照。其次,參考學說上對此所表示之見解,特別是在我國民法第757條明文肯認習慣法得創設物權之後,「事實上處分權」是否構成習慣法物權之論爭現狀,並探討物權法定原則及習慣法創設物權之要件。本文認為習慣法物權仍以符合民法第1條之習慣法為要件,而在習慣法「法官法化」或「判例法化」之下,「習慣法」之「法確信心」要件係由法院之承認與宣示所取代。針對「事實上處分權」是否已具備此要件,本文採否定之見解,「事實上處分權」不僅相異於不動產所有權,亦不構成「習慣法物權」,至多僅能透過類推適用之法學方法,賦予其個別之物權效力。最後,作為類推適用之比較點,本文探討民法上有關所有權規定之各該條文立法理由,包括民法第425條、第425條之1、第426條之1、第767條及強制執行法第15條等規定,並對於目前實務見解,指出值得商榷之處,提出本文對於「事實上處分權」得否類推適用於各該條文之見解,俾供參考。
The thesis attempts to reconstruct legal status of “De Facto Disposal” of unlawful buildings. First of all, by organizing the opinions of our courts, which consider that unlawful buildings belong to real property and negotiable property, this thesis depicts the holistic image of legal status of “De Facto Disposal”. Second, the thesis analyzes the dispute of theories, whether “De Facto Disposal” conforms to a new property form created by customs or not. The custom here is synonymous with the “customary law” which is defined in Civil Law article 1. Although “Opinio necessitatis” is the key element to transfer a custom into a “customary law”, this element has been substituted by the “precedent” nowadays. This thesis considers that “De Facto Disposal” does not constitute a property form created by the “customary law”. Instead, it should only be granted a limited validity of property right through the method of analogy at most. Finally, in order to decide whether to analogize certain articles, including Civil Law article 425、425-1、426-1、767 and Compulsory Enforcement Act article 15 to “De Facto Disposal” or not, the thesis researches on the legislative purposes of those articles, which are standards of analogy, to make the conclusion.