Designing Homes for the In-between Spaces

"Leftover lots" are the object of one Philadelphia-based architecture firm's fascination.

1 minute read

June 8, 2019, 5:00 AM PDT

By James Brasuell @CasualBrasuell


Philadelphia Rowhouses

Mike Linksvayer / Flickr

Jake Blumgart details the work of the architecture firm ISA, which designs "a new generation of uniquely Philadelphian homes […] as architects confront a dwindling supply of available land in growing neighborhoods and seek ways to squeeze housing into what architect Brian Phillips, founding principal of the firm ISA, calls the 'leftover lots'  — the alleys, the side yards, and yes, the courtyards."

ISA is behind an exhibition that debuted yesterday to celebrate rowhouses, which Blumgart calls "the city’s most ubiquitous housing typology." In May, ISA won a 2019 AIA Housing Award for the Tiny Tower, a "slender new take on the "old old Philly row."

"ISA’s tower stands on a narrow back street of Brewerytown, a North Philadelphia neighborhood that’s experienced extensive reinvestment in recent years. Rowhomes line the west end of the block, but vacant lots surround the ISA lot, on the southeastern portion of the block. The roadway is so tight that cars must ease down it, creating a nice quiet block sheltered from bustling Girard Avenue to the immediate north."

Thursday, June 6, 2019 in PlanPhilly

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

July 2, 2025 - Diana Ionescu

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

Person wearing mask walking through temporary outdoor dining setup lined with bistro lights at dusk in New York City.

Restaurant Patios Were a Pandemic Win — Why Were They so Hard to Keep?

Social distancing requirements and changes in travel patterns prompted cities to pilot new uses for street and sidewalk space. Then it got complicated.

June 19, 2025 - Diana Ionescu

Aerial view of new neifhborhood under construction with enpty lots in foreground.

In California Battle of Housing vs. Environment, Housing Just Won

A new state law significantly limits the power of CEQA, an environmental review law that served as a powerful tool for blocking new development.

July 2 - CALmatters

Low-rise Pearl Sreet mall in Boulfer, Colorado.

Boulder Eliminates Parking Minimums Citywide

Officials estimate the cost of building a single underground parking space at up to $100,000.

July 2 - Boulder Reporting Lab

Two-story buildings with porches in walkable Florida neighborhood.

Orange County, Florida Adopts Largest US “Sprawl Repair” Code

The ‘Orange Code’ seeks to rectify decades of sprawl-inducing, car-oriented development.

July 2 - CNU Public Square