Duplex: Stacked


A small (2 to 2.5-story), detached structure that consists of two dwelling units arranged one above the other, each with an entry from the street. This type has the appearance of a small-to-medium single-unit house, may include a rear yard and fits on narrower lots than the side-by-side duplex.

Typical Specifications

Lot Front-loaded Alley-Loaded
Width* 45–75 feet 40–70 feet
Depth* 100–150 feet 100–150 feet
Area* 4,500–11,300 sq. ft. 4,000–10,500 sq. ft.
  0.13–0.26 acres 0.09–0.24 acres
Number of Units 2 2
Typical Unit Size 600–2,400 sq. ft. 600–2,400 sq. ft.
Net Density 8–19 du/acre 8–25 du/acre
Gross Density 7–16 du/acre 7–16 du/acre
Parking Ratio* 1–2 per unit 1–2 per unit
On-street Spaces 1–3 1–3
Off-street Spaces 1 per unit max. 1 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 28–55 feet
Depth 28–60 feet
Height (to eave)* 20–24 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 35 feet
Depth 100 feet
Area 3,500 sq. ft.
  0.08 acres
Number of Units 2 units
Typical Unit Size 1,008 sq. ft.
Net Density 25 du/acre
Gross Density 18 du/acre
Parking Ratio 1.5 per unit
On-street Spaces 1
Off-street Spaces 2
Front 15 feet
Side 5 feet
Width 24 feet
Depth 42 feet
Height (to eave) 21 feet
Floors 2.5 stories

Front Loaded

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.