The C Street Co-op packs a punch: Affordable Housing at 60% AMI? Check. Affordable homeownership? Check. Permanently affordable homeownership? Check. Net Zero Energy? Neighborhood walkability? And all this with about 10% of the subsidy required by typical affordable housing apartment buildings? Check, check, and check. Recently completed in Springfield, Oregon, the C Street Co-op has blown the lid off the affordable housing game. How? By changing the rules. Through cooperative ownership, missing middle infill housing, and the straightforward application of Passive House principles, the C Street Co-op is a powerful demonstration of new paradigm for affordable, sustainable homeownerhip for America.