There is also just simple supply and demand in many areas of NA. There aren't enough houses to match demand, so developers don't even really need to focus all that much on cost control when building: you're already making a killing on the initial sale. A new home that sells for $1mil in a neighbourhood vs one that sold 2 years earlier for $700k is not wildly better made, at least $300k more; people are just willing to spend that much more for a limited supply.