It really depends by what you mean by inferior though. Yes, old homes (pre-WW2) were built using old growth wood that is rot and insect resistant. And they over

It really depends by what you mean by inferior though. Yes, old homes (pre-WW2) were built using old growth wood that is rot and insect resistant. And they overbuilt the structures in many ways. Of course we have some selection bias as the old homes that were not built well (of which there are many) are simply not standing any longer. So the old homes we see today were probably built very well with the materials of the time. Saying that, those materials (old growth wood) aren't around anymore. I think the industry went through a bad patch from the 1950s through the early 90s where A LOT of construction was bad and we didn't really know what we were doing with the sudden change to engineered materials. We didn't really understand vapor barriers because old homes didn't have them and didn't need them. They dried themselves out because they were so drafty and the old wood wouldn't rot easily. So when we moved to rapidly grown pine and engineered wood and insulation we didn't account for moisture very well and those homes have rot issues. Then we came up with water barriers but didn't account for water vapor and moisture would slowly get trapped over time and begin to rot the structures. However, today we have an excellent understanding of what make for a quality dwelling. We understand insulation extremely well - where to put it, what type to use where, how to keep it dry), we understand vapor barriers very well and they are made to block liquid water but allow water vapor to pass outside, etc. Windows have excellent R-values today compared to old homes as well. But yes, you can build cheap homes today that are crap. Code does reel you in a bit but I've heard of code in some areas being so bad it would allow you to sheath a house in cardboard essentially. Insane.