Phius Standards, Certification, and Quality Assurance
Phius Standards, Certification, and Quality Assurance
This domain tests how a project moves from design to certified passive building: which Phius standard applies, what limits must be met, what documentation is required, and how QA verifies the built result. Expect process questions and simple compliance checks.
Core rules and concepts
- Phius certification families include CORE for passive building performance, ZERO for net-zero energy, and REVIVE for retrofits. Confirm the exact edition and program before modeling.
- Core compliance combines demand limits, source-energy limits, and airtightness. A common CORE threshold is 0.6 ACH50; always use the current standard table for the project edition.
- Certification requires a qualified professional, a submitted WUFI Passive model, drawings, specifications, and QA documentation. The model must match the built enclosure.
- QA includes blower-door testing, ventilation commissioning, and photo documentation of critical details. Test early enough to fix failures.
- Changes during construction must be re-modeled or justified; substitution without review breaks certification.
Worked example
A 250 m³ conditioned volume must meet 0.6 ACH50. Maximum leakage at 50 Pa = 0.6 × 250 = 150 m³/h. A blower-door test measures 170 m³/h, or 170/250 = 0.68 ACH50 - a fail. The verifier locates a missing gasket at the attic hatch and unsealed penetrations. After sealing, the retest reads 140 m³/h = 0.56 ACH50, which passes. Convert measured flow to ACH50 using the same conditioned volume used in the model.
Traps
- Confusing ACH50 with natural air changes.
- Using gross volume instead of conditioned volume.
- Submitting a model that does not match as-built drawings.
- Skipping pre-drywall blower-door diagnostics.
- Assuming a product substitution is equivalent without QA review.