I've lived in SF and have heard a decade of talking heads prattling on about building housing, and then looking at the plans and they all end up being gobbledygook about "well if you do 20% Affordable, you can do 50% more units, but if it's 40% Affordable, you can do three more floors," and I keep staring at it and just think... why not just let people build more without doing anything?!?
After thinking about this for years, I realized the system is designed to keep growing property values while offering token subsidized units for literal lottery winners. When you're subsidized units are available to people making 80% of median income, you're not giving subsidized units for poor people, you're building lottery-based subsidized units for normal working class folks. That's bananas.
Just let people build more, incrementally, so homeowners feel like they aren't going to be overwhelmed, but you can still build up.
A simply, effective policy would be to, say, allow anyone to double the amount of sqft and units of the median property in the neighborhood.
That way single family homes become duplexes overnight, and when demand is high enough, duplexes become fourplexes, then when the median unit is a fourplex, you're already got density and you can build up.
None of this extractionary bullshit. None of this "yea, but developers need to pay for housing too." None of the, "well you can do this but not that." Just have simple rules so a homeowner can put a wall up in his house and make a duplex, or add a granny flat, without a bunch of bullshit.