In Practice
A property in an R-3 zone may support apartment buildings or other multi-family structures, with the actual unit count determined by the zone's density controls, floor-area-ratio limits, setbacks, and height maximums. R-3 zones are common in urban neighborhoods that transitioned from single-family to apartment stock in the mid-twentieth century. If you own or are evaluating an R-3 parcel, review the city's development standards table for the zone to understand the density potential and design requirements applicable to your intended project.