What is Passive House?
Passive House is the most rigorous, energy efficient building standard in the United States today. It can reduce building heating and cooling energy use by up to 90 percent. There are over 20,000 buildings, including homes, hospitals and apartment buildings, built to the Passive House standard in Europe. Passive House principles and construction standards provide high quality, healthy buildings that are cost effective and extremely low in energy use. When you start with Passive House, it is a small step to achieve net zero energy use.
Passive House started in Germany in the 1990's. Katrin Klingenberg, an architect, brought the Passive House concept to the United States. She and Mike Kernagis formed the Passive House Institute US (PHIUS) which offers consultant training and building certification.
Passive House is performance based and to be certified a home has to achieve the following performance characteristics:
- an annual heating use of no more than 4.75 kBtu/square foot/yr
- Primary Energy use of no more than 38.1 kBtu/square foot/yr. This includes not only your energy for heating but all the energy used in the home, for example for lighting and cooking. And, it takes it a step farther and includes the energy used by the power plant to produce this energy.
- in addition it has to have an airtight building shell ≤ 0.6 air changes per hour (ACH) @ 50 pascal pressure, measured by a blower-door test.
How does Passive House achieve its goals? There are seven key principals:
- Eliminate thermal bridges
- Make it airtight
- Specify energy- or heat-recovery ventilation
- Specify high-performance windows and doors
- Optimize passive solar and internal-heat gains
- Model energy gains and losses using the Passive House Planning Package, or PHPP
(From: Principles of Passive House Design, Part I. A German Standard Dramatically Can Improve Energy Efficiency of Buildings. By Katrin Klingenberg and Mike Kernagis)
The Passive House Planning Package (PHPP) is a powerful and accurate energy modeling program that lies at the heart of the Passive House design. With it the Passive House consultant can model every aspect of the building's design.