YouTube video
Passive House is a building standard that is truly energy efficient, comfortable and affordable at the same time. Passive Houses allow for space heating and cooling related energy savings of up to 90% compared with typical building stock and over 75% compared to average new builds.
Passive House Institute - resource link
This is my simple (flat roof makes it "modern" [B-)] ) passive house. BTW you can use passive house principles for any kind of structures (house, skyscraper...).
House front
House back
Ground floor
First floor
Flat roof
DOWNLOAD complete house project - 42MB