I'll look into those points.I've heard property owners talk so casually about adding a second or third unit; it led me to think it there wouldn't be a significant issue beyond the cost of the addition.Between meeting with a planner at the county building, reading the municipal code, and learning from people on the forum, this has been a valuable learning experience both in the particulars of adding a unit and generally in doing my homework.So, I'll take the disappointment of not being able to add a third unit in exchange for an education.