The world's first Active House stands at the crest of an estate. Its south-facing roof is covered in solar panels and solar cells, which between them harness more than enough power to keep the occupants warm and the appliances running. In around 30 years' time, if designers have got their sums right, the excess electricity flowing from the house into Denmark's grid will have cancelled out the energy costs of building it, leaving a non-existent footprint on the earth's resources.
As seen on Tiny House Nation May 25th episode. This is a 400sf tiny house that accommodates 2 adults and two children; dining for up to 12; a full kitchen with Island; luxury bath; indoor/outdoor living; totally wired and wireless. Built for the family by Lil Lodges in Alabama then trucked to NY state. If you are a family of two, no second floor is needed so you could have vaulted ceilings throughout. Cost to build/furnish: $100K