> You'd see a lot more 1200sqft new builds if it was more economically viable and developers could make a profit on a $125k home instead of needing $400k.
You do see them, but they are factory built. I could have a $75k manufactured home dropped onto a $20k slab, with $15k utility hookup, and have 3 beds and 2 baths and 1200sqft. It is viable outside of HOAs and "master planned communities" but it is hard to find places in the US that allow this in a "desirable" area.
I agree we need more, but we need smaller too. My parents right now have a 3600 sqft house they will die in, and can't maintain because they are in/approaching their 70s. They built it in 2008 for around $190k when there were still 2 kids at home, my grandmother still lived there, and my sister had a baby on the way.
Now their home is valued at $750k according to the county (after fighting and revising it down from $800k), and if it weren't for all the homestead exemptions and senior rates and whatever other tax breaks they were given, their property taxes would be over $25k/yr.
They've actually tried to sell it a number of times, but 0 bites even discounting it down to $500k, because the town they are in has no comps (single level 4 bed, 4bath on 3 acres).