Difference between building cost and leverage may cover that gap. Let's say you buy a building with a 50 year mortgage for $50M. You're 10 years into the mortg

Difference between building cost and leverage may cover that gap. Let's say you buy a building with a 50 year mortgage for $50M. You're 10 years into the mortgage, so you've paid off $5M. But real estate in your area has done well, so the building is now worth $80M. If the bank forecloses on you then it's risky for them, but not as risky as it sounds. They foreclose and fire sale the building for $60M (25% discount to make sure it moves). They get back the remaining $45M on the loan, and the owner gets $15M. Less than the $35M they'd have if they had sold it themselves. The bank doesn't really care how much the building sells for as long as it's over what they are owed, because that's all they get out of the sale.