In order to be called as a ‘passive house’ a house must be built with certain standards in mind. These standards were created in Europe and hence apply to homes built in the European countries, but are used more or less in the same manner throughout the world:

1. The house should not consume more than 15kWh/m2 in a year for heating and cooling requirements.
2. Its total energy consumption in a year must not be more than 42kWh/m2

In the US, these standards change a little in the following manner:

A house to be called a passive house must be designed in such a way that it consumes 1 btu per square foot per heating degree day for space heating purposes, compared to traditional homes which use anywhere between 5 to 15 btu. Your contractor should be able to explain better what standards he expects to achieve.

Along with these there are also standards for insulation and air-tightness. The structure should not leak air any more than 0.6 times the volume of the house.

Standards of this type make most people think that achieving them will be rather expensive. However, in the long run, the energy consumption of a passive house is less than 25% than that of a normal house. Plus, the overall cost of building, installing and operating a regular house and a passive house are almost the same.