Passive House (Passivhaus in German) is the most stringent building energy efficiency standard in the world. It is not just an energy code or energy design but is integrated with the architectural design of the building to create a wholistic approach to reducing the building’s heating losses and thus decrease the need for expensive mechanical heating equipment. The end result is a house that has a drastically reduced ecological footprint (low carbon emissions), along with superior comfort and indoor air quality.
According to Passive House Alliance United States, buildings that meet this standard use 80 percent less energy than conventional buildings. Specifically this is achieved through maximizing your gains and minimizing your losses. The process begins with strategic design and planning to test “what if” scenarios using certified passive house software. During this process specific climate, siting and sizing is performed to ensure things like windows being positioned to maximize solar gain. Passive house construction uses roughly twice the insulation value of modern code and great care to ensure that the building has no breaks in the thermal envelope. Blower-door air leakage testing is an important component of passive house construction as the standard requires very low leakage to the exterior (0.6 air changes per hour at 50 pascals). Advanced windows and doors are also used to minimize air leakage.
Now that the house is nice and air tight an Energy Recovery Ventilator is used to provide adequate, filtered fresh air for the home. An ERV has the advantage of recycling indoor energy by passing that energy to incoming air further decreasing the heating load on the house. The decreased heating load on the house makes the use of alternative energy to power your building much more attainable and cost effective.
Content from: http://www.phaus.org/learn/passive-house-education/what-is-passive-house-