(a) "SR" Suburban Residence. This is primarily a very low density single-family district and includes areas already developed with low density patterns or logically adaptable for such purposes.
(b) "R-1" Low Density Residence. This is primarily a low density single-family district that is or can be served by community water and sewerage facilities.
(c) "R-2" Medium Density Residence. For areas developed or to be developed at a moderate residential density with single-family and two-family dwellings. Multifamily dwellings are permitted as a conditional use.
(d) "R-3" High Density Residence. For areas developed or to be developed at moderately high residential density with multiple dwellings as well as single-family and two-family residence and served by community water and sewerage facilities.