A net-net-net lease, also known as a triple net or NNN lease, is a type of real estate lease that requires the tenant to pay, in addition to rent, all of the property's associated costs. The three nets in a triple net lease are real estate taxes, property insurance and maintenance costs. Because the landlord shifts these extra costs to the tenant, the rent he charges for a triple net lease is almost always less than for a comparable lease in which the landlord assumes these costs.