Can Millennials Afford Houses?

I see commentary every so often about younger generations not being able to afford the houses like their parents, or grandparents, bought decades ago. These often have a generational warfare tinge to them - "Boomers destroyed the economy and now I have to live in a shack." Even after adjusting for inflation, house prices doubled between 1970 and 2020. But there have been plenty of improvements in the quality of the housing stock making new homes not comparable to parents' houses.

By today's standards Boomers' houses sucked. In 1970, one-in-six US houses had no plumbing and did not have access to public water supply, most of these relied on adjacent well water. Waste water for one-in-four houses was not connected to municipal sewage but used a septic tank or a cesspool. Heating for over a quarter was from room heaters or stoves. Three-quarters had no air conditioning. Washers were in 60% but dryers were in only 40%. These are the measures that the US Census tracked. But we also know from updated building codes that they could not handle as many electric appliances and could not withstand extreme weather as well. 

The clearest sign of progress is how crowded they were. Over the fifty years from 1970 to 2020 square footage increased 70% while the number of people living in the house fell 20%. The available data allow us to track the cost per square foot per person.

Real housing prices double (green line) but so does area per person (blue line) resulting in a nearly constant cost per area per person (red line). I infer that housing costs have not risen but housing amenities have. You could afford your grandparents' house but you probably could not find it anymore, and you probably would not want to live in it.