- Passive Building 101
- The PHIUS+ Standard
- See Case Studies
- Designing Passive
- How to Get Certified
Q: Is the passive house approach only for houses?
A: No! The approach can be successfully applied to any type of building, even skyscrapers. Although plenty of single-family homes have been built to the passive house standard, the design approach is increasingly being applied to multifamily apartment buildings and large commercial buildings. The term "passive building" is gradually coming into more common usage, as it's a more accurate term than passive house.
Q: Does it cost a lot more to build a passive building compared to a conventional equivalent?
A: Passive building typically costs 0-10% more than a conventional building. Generally, the larger the building, the less the cost difference will be. Also, as more large-scale window and door manufacturers bring high-performance products to market, economies of scale drive down costs.
Q: What's it like to live in a passive building? Can you open the doors and windows?
A: Passive buildings are extremely comfortable in all seasons. There are no drafts, temperature variance is extremely narrow (even near doors and windows), and active, balanced ventilation, makes for superb indoor air quality. And yes, passive house owners open their doors and windows just as they would in a conventional home.
Q: Since passive buildings are super airtight, are there any moisture or mold problems to worry about?
A: Passive buildings do require an extremely airtight building envelope, which in combination with superinsulation drastically reduces temperature variations in the building, thereby preventing condensation and mold issues. The constant, low-level ventilation also helps prevent moisture issues in addition to maintaining excellent indoor air quality. That said, potential moisture issues must be carefully addressed at the design stage. That's why it's important to work with a Certified Passive House Consultant (CPHC®). CPHCs are trained to accurately model building performance, and to identify and address potential moisture issues from the onset.
Q: Do passive buildings all have to look the same?
A: Definitely not! Though many early passive homes used an austere European style, passive design does not dictate aesthetics. PHIUS has certified dozens of styles, including Cape Cods, traditional Four Squares, and others.
Q: Are there any certification discounts available for affordable housing developers?
A: Yes, the discount for non-profit developers is 40% off of PHIUS' regular certification fee.
Q: Where do I find windows for my project?
A: PHIUS has certified window data available for a number of manufacturers, as well as recommendations by climate zone. Visit the PHIUS Certified Data for Windows Program resource page to learn more.
Q: How long does the whole certification process take?
A: The length of the certification process varies depending on the specifics of your project. There are three main steps involved:
- Pre-Certification: The length of this step depends on project type, experience of the project team, and at which stage in the process the project team decides to certify, among other factors. The project team will typically receive the first round review about 4-6 weeks after submitting a project for PHIUS+ Certification, after which the team can reply to comments, upload any requested documentation, update the energy model, and send back the completed documentation to PHIUS. Most projects require 3 rounds of review to achieve Pre-Certification. On average this process takes between 6-8 months total, but can vary depending on the project schedule and turnaround time from the project team.
- Project Construction Phase: Duration will vary by project.
- Final Quality Assurance Protocol and On-Site Verification: The PHIUS+ Rater/Verifier performs onsite quality assurance/quality control (QA/QC) protocols. The typical PHIUS review turnaround time once final documentation is received is about 1 month.