Urban Filter: A Parasitic Research Centre That Makes New York's Air Visible Above a 1907 Library

Air surrounds every New Yorker, yet almost nobody sees it. Urban Filter starts from that blind spot and builds an argument around it: if the condition of the air is invisible, architecture should give it a body. The result is a research and learning centre devoted to air pollution, climate change, and urban air quality, attached to a historic public library and shaped, quite literally, like the thing it studies.

Designed by Grace Hernandez, the proposal was shortlisted in Parasitic Architecture 2020. Its host is Epiphany Library, a 1907 masonry building in New York City with a distinct historic facade and a public middle school directly across the street. Rather than replacing the library or competing with it, Hernandez inserts a lightweight contemporary volume into the space between neighbouring buildings and lets the old institution keep doing what it already does well.

A Light Volume Slipped Into the Library's Central Notch

The key move is placement. The parasite slides into the central notch of the host building and rises above its roofline, following the proportions of the existing structure while refusing to imitate it. Where the 1907 masonry reads as solid and grounded, the addition is porous and technologically expressive, defined by a perforated skin, exposed glazed circulation, and suspended volumes.

Contrast is the right call here. A historicist extension would have blurred the story; this one makes the relationship legible. The library stays a library, the new floors carry a specialised environmental programme, and nothing needs to be demolished for the city to gain a new civic function. It is a quiet case for vertical growth as a sustainable alternative to replacement.

A Filter Wedged Between Three Buildings

Hernandez lets form announce purpose. The upper volumes sit between three existing buildings like a large filter cartridge pressed into the urban block, their perforated surfaces creating a porous visual identity that reads from the street. The metaphor could easily have tipped into gimmick, but it is anchored by what happens inside: laboratories, classrooms, exhibition spaces, a courtyard, an environmental screen, and a research deck where air can be studied, measured, and discussed.

That programme list matters because it gives each piece of the filter image a job. The screen and deck put research in contact with the outside air rather than sealing it away in a lab, and the exposed circulation lets visitors see the building working. The architecture behaves less like a sculpture of a filter and more like an instrument.

Research Brought Within Reach of a Middle School

Site selection is where the project earns its civic weight. Libraries are already places of exploration, independent learning, and open access, and Epiphany Library sits near several educational institutions, including the middle school across the street. Hernandez treats this not as background but as infrastructure: researchers, students, teachers, library visitors, and local residents are meant to cross paths through shared exhibitions, demonstrations, workshops, and discussions.

The effect is to shrink the distance between specialised science and everyday life. Air pollution stops being an abstract global statistic and becomes a condition of the streets, schools, homes, and public spaces immediately around the building. Placing that conversation on top of a neighbourhood library, rather than in a remote research campus, is the proposal's most persuasive decision.

Why This Project Matters

Parasitic architecture is often read as an exercise in clever occupation of leftover space. Urban Filter pushes the typology toward something more useful: a way of extending the social relevance of an existing public institution. The host is preserved, its civic role is amplified, and the addition carries a programme that the city genuinely needs, all without the carbon cost of starting over.

Its larger lesson is about visibility. By giving an invisible resource a recognisable architectural form, and by locating its study beside schoolchildren and library patrons, Hernandez turns environmental research into a public act. For a competition about buildings feeding off buildings, it is a thoughtful reminder that the best parasites give something back to their hosts.

View the Full Project

About the Designers

Designer: Grace Hernandez

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Project credits: Urban Filter by Grace Hernandez Parasitic Architecture 2020 (uni.xyz).