Fourplex: Stacked


A detached (2 to 2.5-story) structure with four dwelling units, two on the ground floor and two above, with shared or individual entries from the street. This type has the appearance of a medium-sized single-unit house and may include a rear yard. This type is attractive to developers by generating four units on a typical 50’ lot with alley access.

Typical Specifications

Lot Front-loaded Alley-Loaded
Width* 50–75 feet 45–65 feet
Depth* 100–150 feet 100–150 feet
Area* 5,000–11,250 sq. ft. 4,500–9,750 sq. ft.
  0.11–0.26 acres 0.10–0.22 acres
Number of Units 4 4
Typical Unit Size 500–1,200 sq. ft. 500–1,200 sq. ft.
Net Density 18–29 du/acre 21–35 du/acre
Gross Density 14–22 du/acre 15–25 du/acre
Parking Ratio* 1-2 per unit 1-2 per unit
On-street Spaces 2–3 2–3
Off-street Spaces 1.5 per unit max. 1.5 per unit max.
Front* 10–25 feet
Side* 5–12 feet
Rear (main building)* 30–60 feet
Between Main and Accessory Buildings 10–20 feet
Building Size
Width 34–56 feet
Depth 32–60 feet
Height (to eave)* 20–28 feet
Floors 2-2.5 stories
* Varies based on context

Idealized specifications take the best characteristics of this type and update them for today’s typical building standards, serving as a model for new development.

Alley Loaded

Ideal Specifications

Width 50 feet
Depth 120 feet
Area 6,000 sq. ft.
  0.138 acres
Number of Units 4 units
Typical Unit Size 1,200 sq. ft
Net Density 29 du/acre
Gross Density 22 du/acre
Parking Ratio 1.5 per unit
On-street Spaces 2
Off-street Spaces 4
Front 15 feet
Side 5 feet
Width 40 feet
Depth 60 feet
Height (to eave) 21 feet
Floors 2 stories

The following example(s) show this housing type documented as real-world examples as they exist today. NOTE: Documented examples may be not be up to today’s local building code standards. See the Idealized tab for up-to-date specifications in line with modern building standards.