What is the Passive House (PH) Standard? Developed by the Passive House Institute (PHI) in Darmstadt, Germany, the PH Standard is a voluntary, performance-based energy standard for buildings.
Since the early 1990s, thousands of homes and commercial buildings have been designed and built to the standard throughout Europe.
In the U.
S.
, it has recently picked up speed with projects in various stages of certification across the country.
A PH can save up to 90% on space conditioning costs over a standard code-designed house.
In order to meet the standard, the design must be modeled using the Passive House Planning Package (PHPP), an energy modeling program designed by the PHI.
The software must illustrate that the building's energy use is within the specific limits established by the Institute.
Additionally, a pressurization test must be performed near the end of construction to insure that the required level of air-tightness has been met.
What makes a PH unique? A PH has a super-insulated, airtight envelope which makes its heating requirements incredibly small - so small, in fact, that the house can be heated by its occupants (internal gains) and the sun (solar gains).
Internal gains include heat produced by people, cooking, domestic hot water, and appliances.
Because the house is airtight, there must be a way to ventilate it to prevent problems with moisture and indoor air quality.
That's why all PHs have a device called a Heat Recovery Ventilator (HRV) that constantly ventilates the house with a very low energy fan while recovering heat from the exhaust air.
These systems have efficiency ratings as high as 90% and can eliminate the need for conventional heating.