Does building an ADU in Los Angeles change your property tax?

[Michael Kaminsky]

I recently bought a house in Los Angeles that has a garage qualifying for an ADU conversion. My architect says I have the option of making the ADU two stories, and I'm weighing the pros and cons of doing a small, cheap conversion and a larger, more complex build out with potentially better long term returns. One factor that I don't know enough about is the potential change to my property tax- I'm assuming that the property gets reassessed, but how does the new value get calculated? My back-of-napkin math so far seems to suggest that going for the bigger unit won't necessarily bring in a lot of extra rent, but could add a lot of value when I sell it, so I'd be absorbing a lot of extra taxes for the time I own the property.

Any thoughts or insights would be appreciated,

Michael