The main issue is most new buildings are really bad in terms of insulation and energy performance, even though this has been a solved problem for a few decades

The main issue is most new buildings are really bad in terms of insulation and energy performance, even though this has been a solved problem for a few decades now. The main ideas behind standards such as Passive House do not require any radical changes to house construction, it's just a bit more insulation and building a quality house that is sealed properly (which also means it'll have less maintenance issues). But the construction industry doesn't want to change because that'll mean less profits... If you buy a cookie cutter home it's probably been funded by a hedge fund, who is going to earn a pretty nice return when you buy it. This isn't just a US thing, in most of the Western World it's the same. Building housing is a very profitable business. I live in Northern Europe and the building code here requires insulation and air tigheness levels that actually exceed Passive House. All new houses must have a heat demand of less than 15kW/m2/year. That's in a place where it regularly gets to -25C / -10F in winter. Of course all the big construction companies complained about these regulations when they came out, saying how it would make housing so much more expensive - but at the end of the day it has very little impact on the overall price, and you actually save in the long run due to much lower heating costs.