The Concrete Jungle is about to get a little bit greener with the world’s tallest passive house tower in the works — but only if the building can meet the strict passive house requirements.
According to the Passivhaus Institut in Germany, the passive house is not a brand name, but rather a building standard, designation and philosophy. In order for a building to be deemed a passive house, it must consume 90 percent less heating energy than the average building. This can be achieved by installing special windows and a shell of thermal insulation in the exterior walls and in the paneling of the roofs and floors.
New York City’s passive house residence hall is being built for Cornell Tech’s new campus on Roosevelt Island, and at 270,000 square feet and 26 stories, it’s blowing all other passive houses out of the water in terms of size.
“It’s been an exploratory process for us,” said Architect Blake Middleton of Handel Architects. “Partly because nobody has done anything of this scale.”
Cornell Tech’s new building will feature exterior walls as thick as 14 inches with 11 inches of mineral wood for insulation. The building will be made with prefabricated panels, which means each wall of the tower will be constructed panel by panel in small sections, rather than having to transport large, pre-built units to the construction site. The building will also sport triple-glaze windows, which are thicker than the standard single or double-glaze, and reduce condensation as well as cold drafts and wind noise. Although triple-pane windows are meant to increase efficiency and save energy, skepticism remains over the effectiveness and cost benefits of triple-glaze windows versus high-end double-glaze windows.
The biggest challenge the building will face will be when it’s tested for air changes per hour. At 26 stories, the tower will be affected by the wind more so than a shorter structure would be. The panels have to be installed and sealed perfectly to avoid air coming in and out of the building when it inevitably flexes on a windy day.
Any building can be a passive house — from offices to apartment buildings to family homes. And with the current state of climate change, it could be exactly what our planet needs.
“It is a clear signal that in today’s era of climate change, it’s not enough to simply build tallest,” New York Passive House President Ken Levenson said. “To lead the market, your tall building will need to be a passive house.”
Levenson believes the passive house movement is the “boom heard round the low-energy, high-performance world,” and that “if passive house can make it in New York, it can make it anywhere.”