A rental agreement is an agreement by which one party binds himself to give the other party the enjoyment of an item, for a certain time. When the parties choose to make a written agreement regarding the rental of land and house buildings, it tends to be made under their own hands with sufficient stamp duty. There is a lack of awareness about the importance of the law and considers that land and house building rental agreements are just ordinary transactions and are customary practices to meet the need for housing. In practice, making a private rental agreement can experience several obstacles. The author examines cases regarding rental agreements made privately that are disputed in court, namely the case that occurred in Supreme Court Decision Number 1078K/Pdt/2021. The basis of the plaintiff's lawsuit is that the actions taken by Defendant I and Defendant II, namely asking the Plaintiff to vacate the leased object, can be categorized as an act of "Default/Breach of Promise". This research aims to find out whether there is a rational basis for the judge's decision which states good faith as a basis for canceling the agreement and whether there is legal protection for tenants in land and building rental agreements made privately based on Supreme Court Decision Number 1078 K/Pdt/2021.

This research method uses normative juridical research, namely reviewing statutory regulations using a case study approach to clarify the analysis required in this research. The data analysis technique is an analytical perspective and data processing is carried out using deductive thinking. From the results of the research and discussion, it can be concluded that the rationality of the judge's decision is that good faith is the basis for canceling land and building rental agreements made privately based on the Supreme Court Decision Number 1078 K/Pdt/2021. The parties carry out the legal action of renting, but making and signing the agreement leasing without the approval/permission of the legal owner of the rental object. The judge stated that the tenant did not have good intentions, the rental agreement had no legal force and was null and void, and stated that the tenant had committed an unlawful act, so there was no legal protection for the tenant.