This week, the Passive House Accelerator’s happy hour guest speaker was In Cho, of ChoShields Studio, based in Brooklyn, NY. An experienced architect well versed in the language of Passive House, Cho presented on the two-family Gramercy Townhouse project, located in Manhattan. A duplex over duplex, this was a retrofit of a previously small and poorly designed building that needed substantial work to meet the needs of the clients. The clients’ desires were to reimagine the space as one that embodied their love for water, sunlight, fresh air, open space, and calm sounds, a difficult ask for a cramped space in New York City. In order to meet these program challenges, Cho and her team added one-and-a-half stories to the structure, increased the previously low floor heights, and built on a full rear horizontal extension.
Utilizing Passive House design strategy, CHOSHIELDS used multiple materials in order to optimize thermal performance, including poured in place concrete for the foundation and party wall, concrete masonry unit (CMU) at the interior, structural steel, a light gauge metal frame for the vertical addition, as well as a wood frame, and finally multiple façade types – a rain screen façade, solid masonry façade, and an EIFS façade. Through use of these materials, they were able to successfully reach an impressive 77% reduction in energy use, increase the ceiling heights, enlarge the window areas, and increase the sense of space. The clients were very pleased, and likened living in their new Passive House to “being in a mother’s womb, [where they are] insulated and protected, with everything you need: fresh air, perfect temperature, [and more]”. Through her work on this challenging project, Cho both proved that Passive House is for everyone, and learned many lessons, including the need for good timing, good contractors and good communication with the neighbors, and perseverance, patience, optimism and more, as well as an overall embracement of problems.