5 Main Principles of a Passive House:
Climate Appropriate Insulation Levels
Airtight Building Envelope
Thermal Bridge Free Design
High Performance Windows with Orientation & Shading as req.
Continuous Ventilation with Heat Recovery
1. Benefits of Passive House
Passive House reliably delivers up to approximately a 90% reduction in heating and cooling demand and up to a 75% reduction in overall primary energy demand when compared to our existing building stock – meant to aggressively meet the climate crisis carbon reduction imperative while making a more comfortable, healthy and affordable built environment.
- Indoor Air Quality (air filter, pollution, allergies, wild fires)
- Efficiency (low utility bills, smaller solar PV systems to reach net zero, low operational foot print)
- Sustainable, resilient, reliable
- Simplicity and easy to use and maintain
2. Passive House Concept
Passive House is a building standard that relies on a combination of energy efficiency with passive solar and internal heat gains to dramatically reduce space heating demands and allow for simplified methods of providing needed heat. 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 gains and internal heat gains from occupants, cooking, bathing, electrical equipment, etc.
Control of summer heat through passive and active shading, window orientation and passive ventilation helps to limit the cooling load. The remaining minimized heating or cooling demand can then be provided by a small source instead of a larger conventional HVAC system. For most climates, a heat or energy recovery ventilator will provide a constant supply of tempered, filtered fresh air. Using this “fresh air” system not only saves space conditioning costs by “recycling” indoor energy (always exchanging the air entirely never re-circulating stale air inside the building), but also provides premium indoor air quality and consistent comfort.
3. The international Passive House (Passivhaus) standard performance criteria:
Space heat demand max. 15 kWh/m2 (4.75 kBtu/ft2) OR heating load max. 10 W/m2 (3.14 kBtu/ft2) per year.
Airtightness pressurization test result at 50 Pa to be maximum 0.6 ACH (both over-pressure and under-pressure)
Total Primary Energy Demand max. 120 kWh/m2 (38 kBtu/ft2) per year
* All energy used in the building is included: heating and cooling, hot water, appliances, lighting, and plug loads. “Primary or Source Energy” includes the energy required to produce and deliver the energy to the site and can be offset with solar thermal. Photovoltaics (PV) cannot be included in source energy offset calculations.
** All heating and cooling calculations are based on the net usable floor area of the building. If cooling (air conditioning) is required, the annual cooling energy demand must also not exceed 15 kWh/m2.