Passive House

In 2008 while researching cutting edge green building design and energy efficiency, we came upon the "Passivhaus" (Passive House) standard that has been growing over the last 15 years in Germany and Northern Europe. We found the approach to be very appealing, offering a high level of energy energy efficiency and comfort at a relatively low cost.

We wanted to see how Passive House standards might be adapted to the Northwest's climate. We are now not alone in our interest! Recently Passive House has attracted national and local attention with news articles in the New York Times as well as the Oregonian. In 2009, Eric was speaking to local building groups about Passive House along with Tad Everhart. They developed a basic handout that covers the history, basics design principles, performance standards, and resources. Eric also became a Certified Pasive House Consultant by taking the course offered by PHIUS, the US national organization. He is avaiable for talks, training, and to help homeowners and professionals design and build to the Passive House standard.

At its core, Passive House is a performance standard that eliminates the need for a heating system while providing a high level of thermal comfort. This is achieved by creating a super insulated building envelop such that the small sources of heat within the house are sufficient to keep the house warm in the winter. Likewise the building envelop is effective at insulating against warm summer weather as well.

Note that a "Passive House" and a "passive solar house" are not the same. Passive solar homes capture and store heat from the sun. The Passive House relies on the very efficient use of internal heat gains and minimal heat loss. While they are different approaches, they can be used together to significantly minimize the energy needed to keep a home comfortable.

Here is a simplified list of Passive House design principles:

• Super insulation
• No thermal bridging
• Advanced window technology
• Airtight construction
• Efficient heat recovery ventilation
• Compact and simple building shape
• Passive solar design
• Minimal space heating
• Energy-efficient appliances

The Passive House Institute-US located in Urbana, Illinois offers the following description:
A Passive House is a very well-insulated, virtually air-tight building that is primarily heated by passive solar gain and by internal gains from people, electrical equipment, etc. Energy losses are minimized. Any remaining heat demand is provided by an extremely small source. Avoidance of heat gain through shading and window orientation also helps to limit any cooling load, which is similarly minimized. An energy recovery ventilator provides a constant, balanced fresh air supply. The result is an impressive system that not only saves up to 90% of space heating costs, but also provides a uniquely terrific indoor air quality.

Another good overview of Passive House can be found on Wikipedia's Passive House page.

We are very excited to see the growing interest in Passive House and look forward to working with others to explore and demonstrate the benefits of this approach to home design in the Northwest.