I don't think building homes is really prohibitive due to regulations. I know it varies a lot by region of course. But I'm in an area that isn't really effected by earthquakes and has no frost line/need for basement/etc. I've built a few houses as a GC. It's land more than anything that's gone up in the past ~15 years since I first started in it. That's purely a market force. Second is skilled labor, even unskilled labor honestly. There's just a massive shortage of people doing manual labor/sweaty work, and I typically have access to a major pool of immigrants as we border Mexico. In terms of materials, there's some regulated things we have to do more of now, like insulation and other energy efficiency things but it's rather small in the scope of things. I currently own a 1950s built mid-century modern that was built in a time of low regs here. If I were to build it exactly as it is (to past codes) and simultaneously build it again (to current codes), the current code version would only be about 10% more. Likewise, if I demolished it and just sold the land, I'd still get about 90-100% of what it's market rate is right now. That market rate has ~quadrupled in the 15 years I've owned that house and to reiterate, the home itself is nearly worthless. I'm not in a fastly gentrifying area either. I'd say it's affluent but it always has been since I owned it, it's become more common to just knock down the original homes and build new.