Video: Cornell Tech, the World's Largest Passive House

Slated for completion in 2017, the apartment tower on Cornell Tech's Roosevelt Island campus will be the largest Passive House completed so far. This is important not only for the energy it will save, but for the inspiration it will provide: at over 270,000 square feet and housing over 500 graduate students, the simple proof that a Passive House of this size can be built is impressive. Last year, we invited project leaders and industry experts to speak at length about the challenges and opportunities of a Passive House project like Cornell Tech, in collaboration with AIA New York and New York Passive House. Below are eight video highlights from our panel.

About Cornell Tech

Ariana Sacks Rosenberg (Hudson Companies) and Luke Falk (Related Companies), who represent the joint venture developing the tower, joined design consultants Deborah Moelis (Handel Architects) and Lois Arena (Steven Winter Associates) for an overview of the Cornell Tech project. 


What is a Passive House?

In this talk, Falk explains what the Passive House standard is and how it fits into New York City’s building landscape.


The Thermal Envelope

In this segment,  Moelis describes the challenge of meeting Passive House criteria while maintaining the architectural vision. In order to create an appealing indoor-outdoor space, the team faced obstacles like bending the thermal envelope to incorporate outdoor balconies, constructing windows in a controlled environment, and navigating wall thickness and insulation values, while communicating with the contractor through it all.


Passive House Consultants, Windows, and Testing

Here, Arena highlights the goals of Passive House construction that go beyond energy efficiency such as comfort and durability. She relates these topics back to the challenges of window installation and the need to test air sealing throughout construction.


Energy Efficient Heating and Cooling

In this segment, Falk expounds on the team’s surprising strategy to regulate indoor temperature; because the building is so thoroughly insulated, the VRF system is not designed to provide heat at all! Falk explains how this system works and compares global trends in HVAC equipment and design.



In a well-sealed space, the only air movement is intentional air movement through mechanical ventilation: as a result, creating a ventilation plan is a crucial part of the Passive House design and construction process. Falk elaborates on this process and how to comply with (often conflicting) city codes and other green standards.


Duct Sealing

Here, Luke Falk describes the process of creating healthy ventilation without the side effect of unintended air movement.  In order to achieve the right balance, he stresses the importance of well-sealed ductwork that ensures air is moving where and how it is intended.


Unregulated Loads & Sub-metering

Rosenberg and Falk speak on the innovative ways the team is using technology to engage tenants and encourage resource conservation. With real-time tracking and usage-based billing, utility transparency will encourage tenants to modify behavior.


Want to learn more? See the Q&A session from our panel on YouTube.

About the authors

Urban Green Council
Dedicated to transforming buildings for a sustainable future.