What: Passive House Standards

Passive House applies to all building types and can fit any architectural style. (Don't be fooled by the "house" in the name...in the german Passivhaus, the “haus” connotes “building”.) A Passive House can be an apartment block, a school, a museum, a firehouse, a retail store, a hospital, an industrial facility, a high-rise office tower…pretty much any building type you can imagine.

The Passive House approach is perfect for larger buildings because they have inherently more efficient geometries: as a form gets larger, the ratio of its surface area to its volume decreases. For a larger building, that means that the ratio of its envelope (walls, roof, and foundation) to its interior (the spaces that need to be thermally conditioned) decreases. Because Passive House is an envelope-first approach to high performance building, this lower ratio of envelope to interior space makes it easier to achieve Passive House performance in larger buildings. Passive House Intro | Why: Passive House Benefits | How: Passive House Design Principles

Two Standards

In North America, two distinct and independent Passive House standards and certifications are available: one administered by Passive House Institute (PHI, based in Darmstadt, Germany) and the other administered by Phius (based in Chicago, Illinois). (The two organizations are not affiliated with one another.) Each group offers a basic Passive House certification, Passive House net zero options, and a retrofit certification.

The two standards differ in important ways, including Phius’ approach of adjusting a given project’s performance targets based on the climate of that project’s site. Nevertheless, the standards share important commonalities: both focus on three key performance metrics (see below); both standards are firmly grounded in building science and building physics; and both standards require practitioners to employ a common suite of Passive House design principles to achieve their performance targets. To learn more about certification details, please visit PHI and Phius.

Three Performance Targets

Unlike checklist-based green building certifications with their long lists of credits covering a wide range of sustainability measures (eg. LEED® credits for bike racks and native plants), Passive House brings a laser-like focus to building energy performance and quality, specifically to three metrics: thermal energy demand (or load), total energy demand, and building airtightness.

Powerful Digital Tools for Design and Optimization

The Passive House approach is guided by building science and building physics, but you don’t need to be a building physicist yourself to design and build a Passive House. Designers can earn a Certified Passive House Consultant or Designer certification from PHI or a Certified Passive House Consultant certification from Phius. Builders and tradespeople can earn a Certified Passive House Tradesperson or Certified Passive House Builders certification. But a degree in physics is not necessary to harness the power of Passive House design. Instead, digital tools do the heavy lifting on physics calculations and energy modeling, empowering designers to optimize for performance and cost. For PHI certification, the main digital tool is the PHPP (Passive House Planning Package), while for PHUIS certification, it is WUFI-Passive. Supplemental tools like Therm, Flixo, and WUFI provide powerful thermal and hygrothermal analysis as well.