The following applies to Accessory Dwelling Units, Junior Accessory Dwelling Units, and Efficiency Dwelling Units: Accessory dwelling units are allowed in the R-HS, R-R, R-L, R-S, R-M, R-H, R-O, and R-P zones. An accessory dwelling unit shall not be located on any parcel already containing a dwelling unit that is non-confirming with respect to land...