Planned for a site on the banks of the Schuylkill River, The Ridge is intended to become the nation's largest Passive House. Scheduled to be completed in 2014, the building will be prefabricated in a facility just outside Philadelphia.
Sustainable elements include power generated by a 200-kilowatt solar array and a completely permeable, green-roof covering the site.
The technical aspects of solving the net-zero energy puzzle are not the only challenges for Onion Flats. "What's going to be important is to demonstrate that it's easier to meet Passive House standards on large-scale buildings than small buildings," [Timothy] McDonald, [Principal] said. "We want to show that it's not only possible but also much easier to take on larger buildings without losing quality design."