Passivhaus in America

I have been looking at articles recently regarding the Passivhaus method of energy-efficient focused building. This one article on Treehugger offered some critiques on the Passivhaus system. As we all know there are more extreme temperature swings on a seasonal basis in many areas of North America when compared to the more stable European climate from which the Passivhaus standard originated. One critique on the system is that there is a bias towards smaller housings because the system is based on energy used per square foot and offers no "penalties" for building large and smaller houses are apparently harder to certify. The standards for retro-fitting and certifying existing buildings are also apparently very stringent and therefore discouraging to those thinking of renovating. I am glad there are articles describing the negative aspects of a particular rating system so that we can learn the areas of weakness and not accept a standard as infallible.

http://www.treehugger.com/files/2010/04/passivhaus-too-rigid-for-america.php