Duplex: Stacked

Description

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
Units
Number of Units 2 2
Typical Unit Size 600–2,400 sq. ft. 600–2,400 sq. ft.
Density
Net Density 8–19 du/acre 8–25 du/acre
Gross Density 7–16 du/acre 7–16 du/acre
Parking
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.
Setbacks
Front* 10–25 feet
Side* 5–12 feet
Rear (main building)* 30–60 feet
Between Main and Accessory Buildings 10–20 feet
Building
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

Lot  
Width 35 feet
Depth 100 feet
Area 3,500 sq. ft.
  0.08 acres
Units
Number of Units 2 units
Typical Unit Size 1,008 sq. ft.
Density
Net Density 25 du/acre
Gross Density 18 du/acre
Parking
Parking Ratio 1.5 per unit
On-street Spaces 1
Off-street Spaces 2
Setbacks
Front 15 feet
Side 5 feet
Building
Width 24 feet
Depth 42 feet
Height (to eave) 21 feet
Floors 2.5 stories

Front Loaded

Ideal Specifications

Lot  
Width 45 feet
Depth 125 feet
Area 5,625 sq. ft.
  0.129 acres
Units
Number of Units 2 units
Typical Unit Size 1,008 sq. ft.
Density
Net Density 16 du/acre
Gross Density 13 du/acre
Parking
Parking Ratio 1.5 per unit
On-street Spaces 1
Off-street Spaces 2
Setbacks
Front 15 feet
Side 5 feet
Building
Width 24 feet
Depth 42 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.