I absolutely DO know that for sure. I personally tried to build more housing, by actually buying land and building housing. I ended up not being able to because of single family zoning.
Just say you personally want to go out and solve the housing problem, what is stopping you? Like you can just go buy some houses, tear them down, and build more densely. You will definitely make money. That was my thinking and I was prepared to put my money down to make it happen. I was stopped at the planning stage by zoning.
I was under contract to buy land and started the planning for building. I had an idea of how many buildings I wanted to construct, where they would be laid out and was starting to get permits. So I went to the city to start getting approved for permits, I was told by the employee at the city planning department that that was not going to be possible and that the maximum number of homes that could be built on this lot was exactly ONE. Even though the lot could have easily held 5 single family homes, it was zoned for one house.. Meaning that the planning department would automatically decline my permit application based only on the fact that that land had been designated for one house instead of five. That's what "single family" means here. It had nothing to do with the quality of the buildings or their layout.
So I thought that was ridiculous and asked how I could get around that, I was told that I would have to go to the city zoning commission and either get the lot rezoned or get a variance (special lingo for an exception). She laughed at me and said that that was very unlikely to happen.
I went to the zoning commission meeting that was held monthly. Can you guess who runs that commission? Homeowners from the area! Guess what they did not want me to do. Build more housing! Those people do not want to see the character of their town change, they don't want to see anything change. The people in charge of determining what gets built in cities are the people with a vested interest in keeping supply low to maintain their investments. And the thing is that when these zoning laws were set up the cities all basically just copy/pasted from one another, so they all have the same system with only small differences.
Needless to say, I backed out of escrow, did not go through with buying the land, and learned a very valuable lesson about how housing works in the US.
This is a separate issue from building codes. The building standards in the US are determined by codes which have nothing to do with zoning and can be as stringent as one likes.
Take a look at the city of Cupertino zoning map: https://www.cupertino.org/our-city/departments/community-dev...
You will be amazed at how much of the city is single family zoned. Meaning that it is required to be super low density and that even if a developer bought all the houses in a neighborhood they would not be allowed to build any more densely than what is already there.