Marin Builders Association member Burton Builders LLC has published a free set of city-by-city ADU permitting guides covering seven Marin municipalities. The guides are written for homeowners and for the trades who work alongside them, and they are free to read with no sign-up. State ADU law sets the floor, but the day-to-day experience of getting an ADU approved still varies a lot from one Marin city to the next — different height limits, different fee schedules, different rules once a lot is on a