One of my favorite projects is the New Norris House, a creation of the UT School of Architecture. A small, very tight home that achieved LEED Platinum. They have been playing with the passive ability by periodically turning off the HVAC and monitoring the interior tempurature fluctuations and plotting that against ambient. There is nothing technically unusual about this home, good building science with off the shell components. Interior tempuratures in moderate ambient conditions remain within a tolerable range. Imagine an '06 home without HVAC for three days! This structure was assembled by Clayton Homes and finished by UT students for the most part.
        The point is - this ain't rocket science. The question is - why are we not doing this with all of our homes?
http://www.thenewnorrishouse.com/

              There has been a discussion amongst RESNET members on Linkedin about a falsified rating. The home in question scored HERS 55 and has since been reviewed finding several components less than advertised. Should we be surprised?