most circumstances. A lease or hire contract is invalid when the rent is unknown—at times small, at other times large—when the work to be performed is undefined, or when the term itself is not fixed. Likewise, one may not hire a labourer on the basis that he will pay him “whatever people normally pay,” if that customary wage differs from place to place.

Whoever rents a house or a shop for a known period does not owe the owner any rent merely by concluding the contract unless immediate payment is expressly stipulated; if it is so stipulated, it is permissible. When paying the rent in cash, the parties must set a definite time for payment—such as the beginning, middle, or end of the month, month by month, or according to any arrangement they choose. If they name no time, the rent falls due immediately, and the landlord is entitled to it as each portion of the term elapses. Thus, whenever a day or more has passed, the owner of the property is owed the rent for that elapsed time, unless a widespread local custom dictates otherwise, in which case the absence of an explicit condition is interpreted in light of that custom.

If the rent stipulated is ambiguous and yet the lease is concluded, the contract is defective and non-binding; for the time already elapsed the parties must revert to the prevailing market rate for comparable property or labour. A lease is not dissolved by the death of either of the contracting parties; each one’s heirs simply take his place. Nor, in his view, is it dissolved by a subsequent sale.

If someone leases a house or land and then sells it without disclosing the existing rental agreement, this counts as a defect that entitles the buyer, should he so wish, to rescind the purchase, or to proceed with it while bearing the obligation of paying the rent—unless only a short term of a few days remains, in which case he has no option.

Whoever rents a house for a specific year or for a specific month may neither leave nor be evicted by the landlord until that year or month is complete, unless both parties mutually agree to dissolve the lease.