Designed to reduce energy consumption by 90%, passive house standards are some of the most stringent concerning the construction of residential and commercial projects. Passive homes are incredibly well-insulated and are built to be as air tight as possible. Heating is mostly solar, with any remaining heat coming from electrical equipment and people inside the house. This means that any remaining need for heat comes from a small power source.
In the case residents need to cool down, window placement and shading is a major component in keeping the building cool during summers. By using these means, passive houses minimize the heating and cooling load, and in the long run, reduce energy consumption and carbon emissions.
In order to make these homes as airtight as possible, Passive Homes have a tendency to be simpler in design, and often box shaped. This is to reduce the number of joints in the house, which minimizes the potential for air leakage. As seen in the Hudson Passive Project created by Dennis Wedlick and Bill Stranton, this box-shaped building and tall roof was inspired by the Iroquois longhouses that were part of the Hudson valley landscape for centuries. With the added space from the roof height, not only is more warm air stored in the house during the winter, but it allows air to vent up and out of the home during the summer.
Walls are built thicker than the usual home, and the overarching goal during construction is to build a great quality home up so as to prevent as many repairs as possible. Windows should be glazed and the largest windows in the house should face the equator and windows facing the East and West should have shades to prevent overheating.
By building the house to be as airtight as possible, Passive House standards allows for a home to function with 10% of heating/cooling energy found in a typical three bedroom house. This means, there is no need for solar panels, geothermal energy sources, or even wind turbines. It also translates into a house that can withstand locations and environments with drastic weather changes. While Passive House is an international organization with a majority of the homes based in Europe, they have slowly been expanding to the United States. However, because Passive House standards are incredibly stringent, they have not taken a huge foothold within the U.S. in comparison to other green building standards such as LEEDS. Despite this, the Passive House Institute, which can be found internationally, hopes to grow and expand these standards for more green housing and a healthier planet.