This is an under appreciated reason cities can’t add enough housing: Even when the zoning changes, a multitude of other rules still force low density. SLC, for example, allows ADUs, but things like setbacks and max lot coverage rules make them impossible in most places https://twitter.com/YIMBYhvg/status/1301516419234893824

For example, allowing apartments in backyards doesn’t really matter if you can’t build within 10 feet of the edge of the property. Or if you can only cover 40% of the lot with buildings. etc.

If your city has rules like that (which SLC and most US cities do), allowing a bit more density is not a meaningful policy change. It’s either a mostly symbolic move, or it’s a handout to wealthy homeowners bc they’re the only ones w/ enough land to build income-generating apts