A bank *can* require this--it's not a legal obligation, but banks are allowed to put restrictions or conditions on their loans, since ultimately, it is voluntary on the part of banks to make loans; that is, the bank freely chooses to make loans (they don't have to) and so can choose the conditions for the loan. Banks do give often different loans for a primary residence vs an investment prperty, and the primary residence loans are often more favorable--your landlord could have applied for a primary residence loan, which would require that he actually use it as a residence, at least for some period of time.If you have a signed lease however, the landlord would be in breach of lease if he removes you to use the home as a primary residence, and you could sue him for compensation, such as any additional costs you incur due to this.