PASSIVE HOUSE TECHNOLOGY
 Architecture by Justin Pauly, jtp@paulydesigns.com - 831.240.7765
INTRODUCTION
The Passive House concept represents today's highest energy standard, with the promise of reducing the energy consumption of buildings by up to 80% while providing superior comfort and air quality - all at minimal additional upfront cost. When coupled with renewable energy systems, such as solar, Passive House puts true zero energy buildings within reach.
HISTORY & ORIGINS
The Passive House (”Passivhaus”) concept was developed in Germany in the early 1990s by Professors Bo Adamson of Sweden and Wolfgang Feist of Germany. Drawing on Super-insulated and Passive Solar ideas from North America and “Low Energy” European building standards, the concept of a building that could be practically constructed to maintain a comfortable interior climate without conventional heating or cooling systems was devised, tested and proven. The Passive House remains comfortable without large "active" mechanical systems, hence the term "Passive."
In 1996, Dr. Feist founded the Passivhaus Institut in Darmstadt, Germany, to develop and promote the standard. Since then, more than 15,000 Passivhaus buildings have been constructed worldwide. The first Passive House in North America was built in Urbana, Illinois, in 2003 by German architect Katrin Klingenberg. Klingenberg established the Passive House Institute US (PHIUS) in Urbana with builder Mike Kernagis, and in January 2008, PHIUS was authorized by the Passivhaus Institut in Darmstadt as the official certifier of Passive Houses in the US.
Architecture by Justin Pauly, jtp@paulydesigns.com - 831.240.7765
CONCEPT
Passive House is a building concept that relies on a combination of energy efficiency, passive solar, and internal heat gains to eliminate the need for a conventional HVAC system. The concept is implemented through stringent performance standards for airtightness and energy consumption, and verified with a field tested energy modeling program, the “Passive House Planning Package” (PHPP). The energy consumption limits are developed through extensive research on climate change imperatives, economic feasibility, building durability, occupant comfort, and indoor air quality.
A Passive House is a very well insulated, virtually airtight building that is primarily heated by passive solar and internal heat gains from occupants, cooking, bathing, electrical equipment, etc. Control of summer heat through shading, window orientation andpassive ventilation helps to limit the cooling load. Any backup heating or cooling demand is provided by an extremely small source instead of  a conventional HVACsystem. A heat or energy recovery ventilator provides a constant supply of tempered, filtered fresh air. Using this “fresh air” heating and cooling system not only saves space conditioning costs by “recycling” indoor energy, it also provides excellent indoor air quality and consistent comfort.
ECONOMICS
The economic principle behind Passive House is based on a concept by Amory Lovins of the Rocky Mountain Institute to reduce construction costs through energy efficient design. By dramatically increasing the energy efficiency of a building, the HVAC system can be downsized to the point that the mechanical cost savings significantly offset the efficiency investment. This efficiency “sweet spot” is a basis for the Passive House performance standards and the key to its financial feasibility.
BENEFITS
• Low energy use: Up to 90% less heating/cooling energy use, 60-80% overall energy savings
• High quality indoor air: Controlled ventilation for a continuous, consistent supply of fresh air
• Comfortable indoor temperature: 20ºC/68ºF in winter, night cooling in summer
• Operational and construction savings: Vastly reduced utility bills; elimination of conventional HVAC system; much smaller solar systems required to reach zero energy; durable, tight building shell for lower maintenance, etc.
 • Proven sustainability: 20,000+ buildings worldwide, some zero and even positive energy.
PERFORMANCE CRITERIA
• Maximum heating or cooling energy: 15 kWh/m2 (1.4 kWh/ft2 or 4800 Btu/ft2) per year
• Maximum total source energy: 120 kWh/m2 (11 kWh/ft2 or 38,000 Btu/ft2) per year
(“Source Energy” includes the energy required to produce and deliver the energy to the site, and can be offset with solar thermal and other measures. Photovoltaics cannot be used to offset this energy but are recognized.)
• Maximum air leakage: 0.6 air changes per hour at 50 Pascals (ACH50), ~0.03 ACHNAT
APPROACH
• Accurate climate- and site-specific energy modeling with PHPP
• Superinsulation (project specific)
• Elimination/mitigation of thermal bridges (insulation gaps)
• High performance windows and doors (project specific)
• Optimized passive solar design (solar gain in winter, shading in summer)
• Airtight shell with mechanical ventilation and heat recovery (”recycles” 8-15 times the energy used for ventilation)
CERTIFICATION PROCESS
• Accurate compliant modeling with the Passive House Planning Package (PHPP)
• Third party verified blower door test, 0.6 ACH50 maximum
• Record of adjustment of ventilation system
• Declaration of Construction Supervisor
• Photographic Documentation
MORE INFORMATION
• The Passive House Institute US (PHIUS): www.passivehouse.us
• Passive House California: www.passivehousecal.org
• The Waldsee BioHaus (A residential language school built to Passive House standard in Northern Minnesota; the first certified Passive House in the U.S.): waldseebiohaus.typepad.com
• The Tahan Residence (A Berkeley Passive House retrofit in progress, first retrofit in the U.S., first Passive House project in California): www.nabihtahanarchitect.com
• The Passivhaus Institut (PHI): www.passivehouse.com/07_eng/index_e.html
• The Passive House Alliance, US (PHAUS): www.phaus.org
The Passive House Fact Sheet was created by Graham Irwin, Essential Habitat |
