R4 districts allow all types of housing at a slightly higher density than permitted in R3-2 districts. The floor area ratio (FAR) of 0.75, plus an attic allowance of up to 20% for inclusion of space under a pitched roof common to these districts, usually produces buildings with three stories.

To accommodate a potential third floor beneath a pitched roof, the perimeter wall may rise to 25 feet before being set back to the maximum building height of 35 feet. Front yards must be 10 feet deep or , if deeper, a minimum of 18 feet to provide sufficient space for on-site parking and prevent parked cars from protruding onto the sidewalk.

Detached houses must have two side yards that total at least 13 feet and each one must be at least five feet wide. Semi-detached buildings need one side yard with a minimum width of eight feet. The maximum street wall length for a building on a single zoning lot is 185 feet.

One off-street parking space is required for each dwelling unit. Height and setback requirements may be waived by authorization of the City Planning Commission.

On blocks entirely within an R4 zone, optional regulations may be used to develop infill housing when the area is already predominately built-up. A higher FAR of 1.35 is available for qualifying sites, as well as 55% lot coverage, allowing for much larger buildings with more dwelling units. Off-street parking is generally required for two-thirds of the dwelling units.

R4-1 districts permit only one- and two-family detached and semi-detached residences. Despite a narrower lot requirement of 25 feet for detached homes, houses in R4-1 districts tend to be larger than those in R3-1 districts because of the higher floor area ratio (FAR) of 0.75 plus an attic allowance. The perimeter wall may rise to 25 feet before sloping or being set back to a maximum building height of 35 feet.

The amount of required open space on R4-1 zoning lots is governed by yard requirements. Two side yards that total eight feet must be provided for a detached residence. Although there is no minimum width for each side yard, there must always be eight feet between buildings on adjacent zoning lots. One four-foot side yard is required for each semi-detached residence, which must be on a lot at least 18 feet wide. Zero lot line residences are permitted in R4-1 districts, and require only one eight –foot side yard. Front yards must be at least 10 feet deep and at least as deep as an adjacent front yard, up to a depth of 20 feet.

One off-street parking space is required for each dwelling unit. On lots less than 35 feet wide, parking must be located in a driveway along a side lot ribbon.