Hi Jim, funny we should meet. I am a GREEN Realtor. Did you even know there WAS such a certification? :-)
It would be rare to find a ZERO energy use home, as I agree with my one colleague: they have not quite made their way to the marketplace, however, there are certainly VERY LOW energy use homes. There is one self-sustaining home but it is north of $2 million. You would have to email me your price range.
Contact me if you want to meet for an initial consultation so I can send you my list of GREEN homes within about 10 miles of Horsham.
I have homes that contain one or more of the following features: LEED certified, geothermal heat/cooling, green rooves, solar shingles, etc. Some have a modern design and have been featured in architectural magazines, so you are not sacrificing style. One is even a geodesic dome!