PASSIVE HOUSE

WHAT IS A PASSIVE HOUSE?

A Passive House is a very well insulated, virtually airtight building that is primarily heated by passive solar gains and internal heat gains from occupants, cooking, bathing, electrical equipment, etc. Passive Houses are the most energy efficient homes and therefore a big contribution towards climate neutral living.

The Passive House building design standards were originally established in Germany ("Passivhaus") and the success of these principles have led builders to apply them in commercial and residential projects around the world.

Find beautiful examples of Passive Homes in California like Zero Cottage in San Francisco (see photo): California's Energy Future - Passive House California.

There are two Passive House organisations - one based in Germany and another located in the United States - that publish somewhat different Passive House building standards. After comparing the German (often called "International") and the U.S. Passive House standards, we opted to follow the International standard. You can visit their websites to learn more about Passive House Institute in Germany and Passive House in the U.S. - called PHIUS - to decide for yourself which is best for your project.

After completing the construction of the envelope of our house, we conducted preliminary tests of airtightness in our home using a "Blower Door Test." This test determines the number of times, measured in Air Changes per Hour (ACH), that the volume of air in our home exchanges with the outside atmosphere by permeating our home's envelope. We were pleased to find the results show that our house may actually meet the higher threshold for new home construction of 0.6 ACH, more airtight than the requirement for renovations of 1.0 ACH. The final test will take place only after our mechanical ventilation systems are in place in 2025.

THE BLOWER DOOR TEST

HOW DO WE ACHIEVE PASSIVE HOUSE?

Installing windows and doors with high insulation values
Adding external insulation
Designing our facade to maximize passive solar heat gain during winter days.
Reducing "thermal bridges" in the house envelope where building materials like fasteners can conduct heat between the interior and the exterior of the building.
Installing a heat recovery ventilation (HRV) system. The heat recovery ventilation ensures that the house is ventilated year-round without heat loss, especially during very hot or cold days when you would not want to open windows. That's why Passive Houses have a very high indoor air quality.
Using only LED lighting and other energy saving devices.