Vacant lot Zoned RT4 Per Milwaukee Assessor: RT4 District. The purpose of the RT4 district is to promote, preserve and protect neighborhoods intended primarily for 2-family dwellings while also permitting a mixture of single-family dwellings and small multi-family dwellings of 3 or 4 units. This district, much like the RT3 district, allows smaller lots, smaller setbacks and a higher lot coverage than the RT1 and RT2 districts. The neighborhoods found in this district were platted and developed, in large part, in the late 1800s and early 1900s. This district also allows traditional corner commercial establishments commonly found in urban neighborhoods. No HOA or Builder requirements that list agent is aware of. Licensee interest.