By Chloe Kellner, Intern, Building Energy Exchange

This year, Pratt Institute is hosting the Ice Box Challenge for the first-ever collegiate design-build. The Ice Box Challenge is a public installation that demonstrates the principles and impact of Passive House construction by showing how effectively Passive House buildings maintain a structure’s interior temperature without reliance on mechanical systems. Passive House buildings utilize well-insulated envelopes and ultra-airtight construction to dramatically reduce energy use, improve comfort, and create climate-resilient buildings of all sizes. Compared to conventional construction, Passive House buildings realize significant energy performance benefits—up to a 90% decrease in heating and cooling demand, and 75% reduction in overall energy use.

To illustrate these principles in action, Professor In Cho and her architecture students at Pratt are building one box to local building codes and another to Passive House standards. The final design is being built by the whole group in a modular fashion for easy transportation and re-use for educational purposes.

Preliminary design rending. credit: In Cho, Passive House for Everyone!, 2023

On May 1st, the boxes will be filled with half a ton of ice and sealed. One week later, the boxes will be opened to reveal how much ice is left standing in each box, illustrating the dramatic impact of Passive House-level airtightness, insulation, and thermal performance. The event is organized by The International Passive House Association and Passive House for Everyone!, a widespread organization bringing awareness to Passive House design through the creative arts and hands-on training.

“The Ice Box Challenge project is more than just an exercise in sustainable building techniques; it’s a movement to inspire the next generation of builders, designers, and everyone to engage in climate action.  Working with my students on this project has been incredible. Seeing their excitement and energy as they learn about building sustainability and putting their knowledge into practice gives me hope for the future. By raising awareness within our school and communities about the importance of environmental and social resilience, we can empower the next generation to build a thriving and equitable world.” said In Cho, AIA, CPHD, Co-Founder of Passive House For Everyone and ChoShields Studio.

Pratt student proposals. credit: In Cho, Passive House for Everyone!, 2023

This event at Pratt continues a tradition of Ice Box Challenges hosted around the world, starting in Germany in 2016 and traveling to Canada, the U.S., Australia, Chile, and the UK. The last time the challenge came to New York was in 2018, organized by Building Energy Exchange, the NYC Mayor’s Office of Sustainability, and the Brussels-Capital Region of Belgium. The boxes’ exteriors were designed by renowned Brussels-based street artist, Oli-B, who helped create an eye-catching and engaging installation. After one month in the sun, the Passive House box retained 42% of its 1,800-pound block of ice, while the box built to New York building code was left with only 126 pounds—just 7% of its original size.

Passive House has been gaining traction in the New York market in response to a rapidly expanding set of codes and regulations aimed at improving building energy and carbon performance. The House at Cornell Tech, located on Roosevelt Island, is one of the tallest residential Passive House buildings in the world, designed to perform 30% more efficiently than ASHRAE 90.1 standard code. The Sendero Verde building complex (partially constructed and rented) will be the largest fully affordable Passive House building in the world, modeled to consume 60 – 70% less energy than a typical building of its size. At Beach Green Dunes, an affordable housing complex in Edgemere, Queens built to the Passive House standard, residents pay around $10 monthly for summer cooling costs.

On May 8th from 12 to 2pm, Pratt is hosting the reveal event featuring guest speakers, student presentations, and music at their Brooklyn campus to showcase Passive House in action and the work of Pratt’s architecture students. Register below, make your guess for how many pounds of ice will be left in Pratt’s boxes this year, and join us in celebrating high-performance, high-comfort design for all.

RSVP: Ice Box Challenge Reveal (May 8, 12-2pm; bonus exhibition on campus 2-3pm)


The event is hosted by Pratt Institute, coordinated by Passive House For Everyone, and made possible by generous donations from advocate sponsors: Sto-Corp, Rockwool, 475 High-Performance Building Supply, Klearwall, Square Indigo and Passive House For Everyone.   And is further supported by the International Passive House Association, Passive House Network, NYC DOE Office of Sustainability, Passive House Accelerator, Building Energy Exchange, Building Action Coalition, New York Passive House, Zehnder, Cascadia Clip, and Knightwall.

Design Team

Student Participants:  Kelsey Delahunt, Jeremias Emestica, Khushali  Jain, Tyler Haas, Yuxin  Li,Emerald  Liang,  Angie Widjaja, Maxwell  Wolfe,  Shruti  Sridhar, Vivian – Weiwei Sun

Professor: In Cho AIA, CPHD, Co-Founder of ‘Passive House For Everyone’ (PHFE) and ChoShields Studio


  • Passive House / High Performance
  • Passive House

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