Beach, pier and flyby shots might be done with a combination of stock footage, or a single day shoot for filler. Theres a term for it, not sure what it is.
The most recognizable building would be the one their office was set in, which is actually the White Rock Museum & Archives building (a former train station) in White Rock, near the pier.
I noticed more than one scene where it was actually raining, but they digitally edited it out (as best they could on a TV budget). I always thought it was weird for a place with such perfect weather that they could not delay shooting by a day.
It’s a great show. But yeah if look closely, those shoreline shots have rockier beaches and more evergreens lining the shore than should really be the case in Santa Barbara :)