What is Passive House?

Unmatched energy efficiency with the most stringent standard in America

If you’re looking to achieve the highest energy standard in home building today, The Passive House concept is your best choice. With careful design, a home built to Passive House Institute US (PHIUS) standards can achieve up to 90% energy savings compared to code built homes, which is great news for the homeowner and for the environment.

But what is Passive House? At its very core, a passive house limits the use of active systems, such as furnaces and air conditioners, and employs non-active, or passive, concepts to bring the building as close to zero energy as possible. The types of systems employed in a Passive House design normally include the following:


  • Strategic orientation of the building, window placement, and shading to maximize daylighting and optimize the building for solar heat gain and loss (depending on the time of year).

  • An energy recovery ventilator to capture heat from outgoing air and to ensure a constant, fresh supply of air.

  • Triple-glazed windows, super insulation, thick walls, minimization of thermal bridging, and an airtight building exterior.

Essentially Passive House is an extremely well-insulated, air-tight building design that minimizes energy inefficiencies. By using an efficient design, the heating and cooling systems can be significantly smaller than conventional homes, saving energy throughout the year. And overall, the indoor air quality in a Passive House is extremely good.

The following are some of the basic performance characteristics of a Passive House:

  • Airtight building shell ≤ 0.6 ACH @ 50 pascal pressure, measured by blower-door test.

  • Annual heat requirement ≤ 15 kWh/m2/year (4.75 kBtu/sf/yr)

  • Primary Energy ≤ 120 kWh/m2/year (38.1 kBtu/sf/yr)

  • Window u-value ≤ 0.8 W/m2/K

  • Ventilation system with heat recovery with ≥ 75% efficiency with low electric consumption @ 0.45 Wh/m3

  • Thermal Bridge Free Construction ≤ 0.01 W/mK

The US Department of Energy (DOE) has estimated that buildings contribute 48% of all greenhouse gas emissions and consume 76% of all electricity generated in America every single year. As such, buildings offer significant opportunity for mitigating climate change and creating more sustainable lifestyles. The Passive House concept is the most promising for achieving drastic energy reduction potential in the building sector and substantially reducing consumer utility bills. It’s the green building standard to beat.

How to Achieve Passive House Certification with Evergreen Certified

Expert guidance through the Passive House Standard process

Passive House concepts mean extraordinary energy efficiency, and that’s what you get with Evergreen Certified services. Whether you want to modify your existing green home designs to Passive House standards or create a Passive House design from scratch, Evergreen Certified can help.

Not only is Tadashi Shiga the first professional in Washington State to become a verifier for Passive House Institute US (PHIUS), he is also certified to consult on Built Green Certification projects and Northwest ENERGY STAR standards, giving you the confidence you need to design the most extraordinarily beautiful, and energy efficient home possible. The following are just some of the services offered by Evergreen Certified to help you achieve Passive House Certification for your project:

  • Detailed Passive House designs

  • Realistic energy modeling using the Passive House Planning Package (PHPP) software

  • Supply of Passive House documentation and certificates

  • Analysis of the environmental and economic benefits of Passive House standards for your project

  • Mechanical system optimization through energy recovery ventilation design

  • Assignment of an accurate HERS Index, which is used to meet the Passive House building energy standard.

  • Evaluation of your design against other standards, including RESNET, Built Green, and Northwest ENERGY STAR.

Achieving the PHIUS+ Certified Standard

The PHIUS+ Certified Standard process involves several steps. Evergreen Certified will walk you through each of them to ensure you achieve your green home goals through PHIUS+ Certification.

  1. Submit your project: We work with you to upload a list of schedules and drawings to the PHIUS certification database, including plans developed through PHPP.
  2. PHIUS review: PHIUS then reviews the plans and schedules, providing feedback and working with the Evergreen Certified to iron out any details.
  3. Pre certification: Once your plans achieve all requirements, they are pre-certified, at which point Evergreen Certified can assist you with the RESNET qualification.
  4. Building and inspection: We work with you to get the project started, assisting with required PHIUS+ Rater reviews an important intervals throughout the project, including on-site inspections and final testing such as blower door testing and ventilation commissioning protocol.
  5. Quality assurance and quality control reports: A PHIUS+ Rater then provides all QA and QC reports, determining if all standards were met. If so, Evergreen Certified will work with PHIUS to obtain final certification as a PHIUS+ Certified project.

A Passive House design is your best defense against rising energy costs and potential energy shortages given its incredibly low-energy principles. Let Evergreen Certified help you bring Passive House concepts to life for your green home project.