Curating the Local

3CURATING THE LOCAL

by Brian Phillips, FAIA, Founding Principal & Creative Director, ISA and Deb Katz, AIA, Principal, ISA

ISA’s design practice is rooted in the local conditions of the Philadelphia context—its physical patterns, cultural history, zoning codes, construction costs, consumer market and climate. The studio’s inquiry-based methodology looks to leverage the city’s local constraints as dynamic drivers of program, form and urbanism, generating unexpected solutions for a variety of building types. Over the past two decades, as the city’s population grew and its market generated a wider array of development potentials, ISA’s projects continue to refine their relationships to site and place while growing in scale and complexity. The following projects represent examples of highly constrained sites for urban housing, where sensitivity to context yielded surprising results.

TINY TOWER

Early waves of redevelopment often begin on sites with standard dimensions, leaving behind the odd-shaped or extra small parcels facing alley streets. Unlocking the development potential of these leftover parcels can be a tool to increase the supply of low-cost housing for a diverse range of lifestyles. A client came to us with one such parcel—a vacant lot measuring just 12 by 29 feet—wondering what could be done with it. Even though the zoning code allowed an as-ofright single-family house with no associated parking, similar adjacent properties were being used as rear parking spaces for the homes facing the larger street on the next block. Further research into the site’s history uncovered the fact that a row of classic Philadelphia Trinities—tiny row-houses typically less than 1,000 sf with single rooms stacking vertically across three stories and linked by a steep winding stair—had been torn down on the block prior to the sale of the parcel. Inspired by the Trinity typology—but looking to expand the traditionally tiny square footage to a more livable 1,250 sf —the Tiny Tower project used a carefully designed vertical circulation strategy to link six levels (including basement and roofdeck) within the 38-foot-tall zoning envelope. While Trin-

Tiny Tower, 2108

Tiny Tower, 2018

ities typically buried winder stairs in the middle of the house to preserve full front and back windows, Tiny Tower seized the extra-shallow parcel dimension as an opportunity to place a feature stair constructed out of folded plate steel at the front of the home. Since the house is so vertical, the stair itself operates as a room—a light-filled procession with oblique views up to the sky and down to the sidewalk. A large window strip defines the front façade, allowing ample light in through the perforated metal stair guardrail, acting like a privacy blind for the rooms within. The design promotes vertical living, occupying the entire footprint of the site in the required setbacks with a lowerlevel window garden, a second level walk out terrace, and a roof deck. With a kitchen at the lower level and tucked away bathrooms on upper ones, each floor is free to define live, work and play in multiple configurations. The experience of going up and down the stair is integral to the daily life of the building, adding a sense of adventure for the occupants. Tiny Tower demonstrates how—for urban dwellers willing to trade quantity of space for quality—small in scale can feel large in amenity and experience.

XS House, 2019

XS HOUSE

As Philadelphia’s population grows, its urban grid of small lots originally containing single-family row-homes faces increasing pressure to add residents and units within its compact parcel footprints. Beyond the dimensional, use and parking considerations typical of zoning requirements, multifamily building configurations on non-standard lots face additional construction type and egress challenges governed by building code. The site for XS House was a sliver of land left behind after a 1960’s-era sunken expressway was constructed through the center of Philadelphia’s downtown business district. The 11-by90-foot parcel lies between Philadelphia’s Chinatown district to the south and a pair of surface arterial streets flanking the 100-foot-wide Vine Street Expressway cut to the north. At the outset of the project, the site was nearly invisible as a developable lot—surfaced in asphalt, it was being used informally by the adjacent property owner as tandem surface parking for two cars. XS House packed seven units onto the site in a dramatically narrow envelope, adding urban density while

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XS House, 2019

preserving the street life and walkable lifestyles of typical Philadelphia fabric. Though the XS House parcel had no height limitation, a typical high-rise building would have required an elevator and two egress stairs, which in the narrow footprint would have left very little area for units. ISA instead proposed a single-stair, stick-frame building which utilized mezzanine levels and projecting bays to maximize the four-story building code limit for a wood-frame structure while providing dramatic double-height interior spaces overlooking the highway. Despite being a four-story building, the 63-foot-tall section connects seven levels of occupied space within its very small footprint. Utilizing the mezzanine portion of the building code expanded four of the seven units by nearly one-third, changing them from very small studio units (380sf) into comfortable one-bedrooms (500sf) with private sleeping areas in otherwise open layouts. Two micro-lofts and a basement one-bedroom flat (650sf) are accessed directly from Vine Street, while the other two micro-loft apartments flank a central stair that also serves upper level two-bedroom bi-levels (850sf each). XS House also addresses the needs of residents and visitors with mobility challenges within a walk-up building configuration—two of the project’s one-bedroom micro-loft units fulfill accessibility requirements with at-grade entry points also serving to activate the street edge along Vine. The project took advantage of the city’s interpretation of the parking portion of the zoning code at the time of development, which allowed zero parking spaces for multifamily residential projects with fewer than ten units. By providing no parking for residents on or off site, the building footprint, number of rentable units, and interior unit area were maximized, the high cost of developing parking was eliminated and walkable lifestyles were encouraged.

REVISITING REGIONALISM

Designing urban housing with context in mind can uncover, amplify and improve the social, economic and urban relationships among people, buildings and neighborhoods. Although architects may not control the many forces shaping housing, those sensitive to local context can find the critical pressure points where change is possible. Leftover lot projects often demand extra effort on behalf of both the design team and the developer, as solving them is an intricate puzzle rather than a prototypical, replicable solution. While unique in their deployment, projects like Tiny Tower and XS House promote naturally occurring market-tempered housing by unlocking the development potential of sites that historically have felt less economic pressure. Engaging with the right clients, the key concerns of neighborhoods, the supply chain for materials, the realtors that influence development decision-makers and the lawyers and investors that understand the value of design is of equal importance as the baseline dimensional and code constraints. Embracing the small batch bottom-up urbanism that many American cities like Philadelphia have been built upon can provide designers with tools for productive critical engagement, producing novel results with potential to make a positive impact on the social fabric of American cities. l

ISA designs buildings, master plans, installations, and conversations that address changing climates, lifestyles, technologies, and urban environments. The firm’s work has been featured in Architect, Architectural Record, DWELL, Metropolis, The Boston Globe, The Philadelphia Inquirer, The New York Times, and on NPR Radio. ISA has won over 70 local, regional, and national design citations, including AIA Philadelphia Silver and Gold Medals, four AIA National Housing Awards, an AIA COTE Top Ten Award, and USGBC LEED for Homes Project of the Year. Brian Phillips was awarded a 2011 Pew Fellowship in the Arts and ISA was named an Emerging Voice by the Architectural League of New York in 2015.