The inclusion of a solar-study to prove adherence to shadow regulation is a standard part of most types of development applications, not just in the USA but around the world.
This kind of build out is regulated for many reasons: property damage, aesthetics, health, and with a renewed focus: energy use. This includes casting shadows over one’s own property.
I mean actually read it. It basically says shadows don’t really matter much and you barely need to worry about them and then goes on to spell out in very clear detail what happens when they do matter so there don’t have to be moronic lawsuits every time someone wants to build a low rise apartment building.
40 feet, times of year, 20% shadow. make a model. At the surface level, they look similar to me. NYC has been doing that for a whole lot longer, I wouldn't doubt their planning department has a more refined process. But it's not like SF is alone in this kind of regulation.
* has smaller time requirements for sunlight; the planning requirements state that an area should have 4-6 hours of sunlight a day, whereas SF looks at if it gets any worse over any time period
* NYC only protects specific kinds of park uses for sunlight, so like sunlight is not material for a basketball court, for example.
