If you want to really address the zoning problem on a cultural level, you have to find a way to create an "expectation" of the quality of life in some category

If you want to really address the zoning problem on a cultural level, you have to find a way to create an "expectation" of the quality of life in some category of multi-unit building which is acceptable to the modal American. It's pretty typical to expect apartments to be noisy, smelly, not-so-private places which are not so desirable to live in. I can't say my own experience living in an apartment has really contradicted this, either. I'm speculating here, but I think that part of the reason people oppose housing types considered unpleasant is that people may be less likely to stay in them if they have the opportunity to move. If you move into a nice unit (house, townhouse, apartment, whatever) in a stiff market, and the market eases up and you can afford to move, you might not, because moving is a lot of work and the expected benefit is small. But if you move into an unpleasant space in a difficult market, you're likely out of there as soon as you have the chance. This might imply that unpleasant housing types are more likely to become vacant during a market downturn, and because of problems associated with vacant housing, people might want to avoid unpleasant housing being constructed near them. The key exception here are the small add-on units recently legalized in San Francisco; because the main unit will remain occupied, issues associated with vacancy and disrepair of the subsidiary unit are prevented. However, there aren't clear standards that determine whether a multi-unit building will be a place people want to stay, whereas SFH are usually for whatever reason expected to retain their occupants. So when I say "to create an expectation", I mean an expectation among the neighbors that whoever moves in is going to like the place they live in enough that they won't move out in five years when the market cools off. And if you expect the market will never cool off, you're also assuming you never solve the housing crisis, which is not a good founding assumption for making plans to solve the housing crisis. I could imagine standards like: external entrances, private outdoor space (balcony), in-unit laundry, sound insulation, and separate ventilation. But those are just my preferences; any actual standards ought to be based on reliable evidence of some kind. It may be possible to survey the kinds of units that people move out of during housing market downturns in order to identify some predictive characteristics which can both influence housing standards and allay the concerns of voters.