最高法院107 年度台上字第1180 號民事判決認為民法物權編施行法第8 條之5 第3 項僅具有債權效力之優先承買權。本文自系爭判決出發，透過與土地法第104 條優先承買權之比較，聚焦討論該條優先承買權之效力應如何解釋。關於基地用益權人優先承買權，規範目的在使房地合一，提升房地利用之經濟效益，而立法者欲貫徹此一目的，便賦予其具有所謂的物權效力。再者，其物權效力之意義，在使其具有對非契約關係之第三人主張之權利，為債權物權化之規定。債權物權化之標的非優先承買權本身，應為行使優先承買權後所形成之買賣契約，並以房屋或建物存在作為其公示外觀。區分所有人之優先承買權，其規範意旨源自處理處分一體性之新舊法適用問題，其背後目的在於盡量使房地利用關係合一、促進利用效益。且該規範狀態與基地用益權人優先承買權皆係針對「基地所有權人」與「對於該基地上存在之房屋建物具有使用收益權之人」。因此本文認為二者具有相當類似性，基於體系與客觀目的解釋，區分所有人優先承買權亦應解為物權效力，以符合規範上一致性，貫徹背後立法目的。又將此一優先承買權解為物權化之規定，此時得以區分所有建物存在作為公示外觀，使第三人對此亦具可知悉性。

According to Supreme Court Fiscal Year 107 Civil Judgment No. 1180, right of first refusal that is formulated in Article 8-5 Paragraph 3 of Taiwan Enforcement Act of the Part of Rights In Rem of the Civil Code only has the effect of obligations. This article focuses on the interpretation of the right of first refusal in Article 104 of the Land Law by comparing it with the decision at issue. The purpose of Right of First Refusal in the Building Site is to unite the ownership of housing and land, so as to enhance the economic efficiency of real estate use. The legislator wants to thoroughly carry out this purpose, so as to give it the so-called the effect of rem right. Furthermore, the meaning of effect of rem right is not to give the holder of the right of first refusal the status of a property owner, but to give him/her the right to assert against non-contractual third parties, which is propertization of obligatory rights. And propertization of obligatory rights is not the right of first refusal itself, but the contract of sale formed after the exercise of the right of first refusal. The fact of building built on the land would be the notice of right. Then the purpose of unit owner's right of first refusal is to deal with the application of the old and new laws on the disposal integration, which also aims to unify the relationship between the land owners and buildings owners, avoid complications, and promote the efficiency of use. In addition, the regulated status and the right of first refusal in the building site are both for "the owner of the base" and "the person who has the right to use and benefit from the buildings and structures existing on the base". Therefore, this article considers that the two are quite similar, and based on the system and objective purpose of interpretation, the differentiation of the owner's right of first refusal should also be interpreted as the effect of rem rights, in order to comply with the normative consistency and to carry out the underlying legislative purpose. This right of first refusal is interpreted as a propertization of obligatory right, and the existence of condominium building can be the notice of right, so that third parties can also be aware of it.