What is Passive Building?
Passive building is a set of design principles used to attain a rigorous and measurable level of energy efficiency within a specific structure. “Optimizing your gains and losses based on climate”, summarizes the approach of a passive design.
According to PHIUS (Passive House Institute, United States), a passive building is designed and built in accordance with these five building-science principles:
- Employs continuous insulation throughout its entire envelope without any thermal bridging.
- The building envelope is extremely airtight, preventing infiltration of outside air and loss of conditioned air.
- Employs high-performance windows (double or triple-paned windows depending on climate and building type) and doors – solar gain is managed to exploit the sun’s energy for heating purposes during the cold season and to minimize overheating during the warm season.
- Uses some form of balanced heat and moisture recovery ventilation.
- Uses a minimal space conditioning system.
Passive building principles can be applied to all building types, from single-family homes to large office buildings.
Passive Design Strategy
Passive design strategy uses a comprehensive set of factors including heat emissions from appliances to keep the building at comfortable and consistent indoor temperatures throughout the heating and cooling seasons. As a result, passive buildings offer tremendous long-term benefits in addition to energy efficiency.
Unmatched comfort: Superior insulation and airtight construction provide comfort, even in extreme weather conditions.
Excellent indoor air quality: Continuous mechanical ventilation of fresh filtered air.
Highly resilient buildings: A comprehensive systems approach to modeling, design and construction to produce strong buildings.
Best Path to Achieve Net Zero/Net Positive: Passive building principles offer the best path to net zero and net positive buildings by minimizing the load renewables are required to provide.
The Performance Standard
According to PHI, North American building scientists and builders were the first to pioneer passive building principles in the 1970s.
Over time, project teams in North America learned that a single standard for all North American climate zones is unworkable. In some climates, meeting the standard is cost prohibitive, in other milder zones it’s possible to hit the standard while leaving substantial cost-effective energy savings unrealized.
The PHIUS Technical Committee developed passive building standards that account for the broad range of climate conditions, market conditions, and other variables in North American climate zones. The result was the PHIUS+ 2015 Passive Building Standard – North America, which was released in March of 2015. That standard has been updated to PHIUS+ 2018. The PHIUS Technical Committee will continue to periodically update the standard to reflect changing market, materials, and climate conditions.