It depends heavily on which year of the 70s you look at (I was using 1974), but yes, it's true, at the very start of the 70s, houses were 3x the price they are now (measured in gold).
You're right - this is even stronger evidence that whereas most people believe houses have increased in value over the last 5+ decades, they have at best remained the same value, and the price increases have simply been the devaluation of the dollar (which incidentally increases in supply at the same rate as house prices increase - roughly double each decade)
http://www.goldchartsrus.com/chartstemp/USHLSPOG.php
You're right - this is even stronger evidence that whereas most people believe houses have increased in value over the last 5+ decades, they have at best remained the same value, and the price increases have simply been the devaluation of the dollar (which incidentally increases in supply at the same rate as house prices increase - roughly double each decade)