While possible, establishing a short-term rental in Santa Barbara is a daunting endeavor. A quick search for "Santa Barbara" on Airbnb will generate as many as 400 vacation rentals, but only a small percentage of these rentals are sanctioned by the city.
Full disclosure: One of them, La Maison Santa Barbara, is mine. It took just over a year to finalize the conversion, from the day my spouse and I bought it to the day it was approved and we received our business license.
Santa Barbara has been enforcing strict rules against short-term rentals (STRs) since early 2017. As the name indicates, short-term rentals are rented for fewer than 30 days. According to the city, “Short-term rentals and home sharing operations are ‘hotels,’” and they may “legally operate in zones that allow hotels.” The STR must also comply with rigid hotel building codes and be located in a nonresidential zone such as R-4, commercial, or manufacturing.