Project Details
- Project Name
- XS House
- Location
- PA
- Architect
- ISA
- Client/Owner
- Callahan Ward
- Project Types
- Multifamily
- Project Scope
- New Construction
- Size
- 5,000 sq. feet
- Shared by
- Madeleine D'Angelo
- Project Status
- Built
This project was selected as a winner in the 2019 Residential Architect Design AwardsMultifamily Housing, Award
In a phenomenon that played out in many American cities during the mid-20th century, the sunken Vine Street Expressway cut a 100-foot-wide swath of demolition through Philadelphia’s Center City. This reckless car-oriented development impacted the Chinatown neighborhood and left many oddly shaped—and sized—sites that still sit as parking lots or similar underdeveloped uses. Local firm ISA designed XS House for one of these parcels, an 11-foot-by-93-foot lot that isn’t much larger than a wide sidewalk setback.
The architects creatively fit a 5,000-square-foot, seven-unit building within this narrow footprint. While technically a three-story structure, the 63-foot-tall envelope reads as a six-story building—its six duplex units’ upper levels count as mezzanines (the seventh unit is a single level in the basement). Zoning allowed façade projections up to 3 feet deep, a dimension that would typically be just a bay window in a standard apartment, but which expanded some of XS House’s tiny units by as much as a third. The rhythmic development of these extensions—which accommodate exterior balconies as well—enliven the façade along the expressway. The architects also capitalized on the structures’ designation as a three-story building, which requires just a single stair, saving considerable area within the small footprint for use as apartments.
Ironically, XS House’s site was so small that it previously accommodated parking for just two cars. The development adds desirable residential density to Philadelphia’s core while thoughtfully healing some of the spatial scars left by auto-centric midcentury urban planning. It demonstrates that good design can often overcome even the most challenging problem.
Project Credits
Location: Philadelphia
Client: Callahan Ward
Architect: ISA, Philadelphia . Brian Phillips, AIA, Deb Katz, AIA (principals); Alexandra Gauzza, AIA, Jason Jackson (studio directors); Matt Underwood (senior designer)
Structural Engineer: Larsen & Landis Structural Engineers
MEP Engineer: J+M Engineering
General Contractor: Callahan Ward
Lighting: Lam Partners
Size: 5,000 square feet
Cost: $1.14 million
Materials and Sources
Exterior Wall Systems: Fiber cement panels; Corrugated metal
Project Description
FROM THE ARCHITECTS:
Philadelphia’s urban renewal era left behind an east-west cut through the city’s urban fabric in the form of the sunken, 100-foot-wide Vine Street Expressway. Philadelphia’s Chinatown neighborhood was one of those disconnected by the expressway, with many of its formerly densely inhabited blocks sliced into odd shapes and sizes. Today, the expressway continues to divide pedestrian activity, while most of the odd-shaped leftover lots are used for surface parking. XS House rejuvenates one such leftover site, adding urban density and street life while encouraging walkable lifestyles. XS House placed seven apartments on the 11’ x 93’ parcel, expanding the extremely narrow footprint with strategic use of bays, mezzanines, and bi-level upper units while maintaining a minimal single-stair core layout. Upper units are accessed from the common stair, while lower units enter directly from the street, activating Vine Street with additional foot traffic. The expanded envelope approach to this project emphasizes vertical living. A single shared stair runs up through the center of the project and individual unit stairs unlock mezzanine levels. Despite being a three-story building, the 63-foot-tall section connects seven levels of occupied space within its very small footprint.
Project Credits:
Project: XS House
Architect: ISA, Philadelphia . Brian Phillips, AIA, Deb Katz, AIA (principals); Alexandra Gauzza, AIA, Jason Jackson (studio directors); Matt Underwood (senior designer)
Structural Engineer: Larsen & Landis Structural Engineers
MEP Engineer: J+M Engineering
General Contractor: Callahan Ward
Lighting: Lam Partners
