The most obvious is that you cannot afford to buy the house in cash and need to make installment payments on it over the next 15 to 30 years. However, even with a mortgage, real estate is one of the largest ways to build wealth.
Even though that is what many pundits want you to believe. That does not mean they are a better deal or better for everyone. However, there are a few specific situations when adjustable loans are a good choice.