For any good idea to take hold it has to be available to everybody. If an energy efficient house costs twice as much then nobody will buy it.
The Net-Zero house concept is appealing as this house will create all the energy that is needed for its operation. In practise these houses can cost double or more to build over standard construction. By focusing on the most cost effective ways of saving energy and by radically reducing the heating system the Passive House becomes the affordable alternative to Net-Zero.
For example, the cost to build 5 Passive Houses would roughly be the equivalent to building four conventional and one Net-Zero houses. The four conventional plus one Net-Zero group of houses would consume over four times the energy as the five Passive Houses and all at the same cost.
The Passive House is the affordable high performance house for everybody.