Not such a great feat. Houses have gone from 2.5 times gross median income to about 9 times gross median income. Therefore even a low interest environment makes them unaffordable.
Paying a house off in 70's and 80's was a piece of cake on a very modest income.
Lots of people love to fool themselves about how tough they did it. The facts are the current situation is untenable for the majority of working families.
