BEO Science — Passive House Services
PHI building certification —
independent quality assurance through design and construction
Certification to Passive House, EnerPHit, or PHI Low Energy Building standard through a structured four-stage review process — from initial design check to post-construction sign-off and certificate issuance.
PHI Certification
Passive House
EnerPHit
Low Energy Building
NZ & AU
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Important: Certification is not guaranteed. It is awarded on the basis of meeting stringent criteria through independent quality testing and verified documentation. Choosing to pursue certification represents a commitment to quality and energy performance — the process provides the framework; compliance must be demonstrated at each stage.
For the full PHI Building Certification Guide, see passivehouse.com — Building Certification Guide (v10c) →
For the full PHI Building Certification Guide, see passivehouse.com — Building Certification Guide (v10c) →
Need Passive House design consultancy alongside certification?
PHPP modelling, envelope design, thermal bridge analysis, and MVHR coordination are covered under our design consultancy service — a separate engagement that prepares the project for the certification process.
See design consultancy →
Overview
What certification provides
PHI building certification is independent quality assurance — a third-party review of the design and construction documentation confirming that the building meets the criteria for the applicable standard. It results in a PHI-issued certificate, a supplementary documentation booklet, and the option of a wall plaque.
Certification is based on submitted evidence at each stage — drawings, PHPP calculations, product data, test results, and construction documentation. It is not a design service: the technical work is done by the design team and consultant; certification reviews and verifies that work against the standard.
What the certificate package includes
- PHI-issued certification certificate upon successful completion of all requirements
- Supplementary booklet with full documentation of the energy balance calculation and all characteristic building values
- PHI certification number for use in project documentation and marketing
- Wall plaque (optional — available for residential projects)
- Listing on the PHI certified buildings database
The Certification Process
Four stages from initial check to certificate issuance
The process follows the PHI certification framework. Each stage has a defined submission and review sequence — we work through these in order, with the project team providing updated documentation at each milestone.
Stage 01
Initial Check
At project engagement
Review of the project for special conditions or edge cases that require specific assessment under the certification criteria. Any non-standard aspects — unusual building geometry, hybrid systems, combined use types, or climate data requirements — are identified and clarified before the substantive review begins. This avoids surprises at later stages when design changes are more costly.
- Review for special conditions or project-specific aspects
- Clarification of how non-standard elements will be assessed
- Confirmation of the applicable standard and certification pathway
- Agreement on the review and submission schedule
Stage 02
Preliminary Review
Design phase
Assessment of the design concepts — insulation strategy, building services, and a preliminary PHPP calculation — for consistency with the certification criteria. This is the stage at which design-phase risks are identified and design changes can still be made efficiently. We allow for two rounds of review following our assessment report to resolve outstanding questions; additional rounds are agreed separately.
- Review of architectural design concepts and insulation strategy
- Assessment of preliminary PHPP calculation against certification criteria
- Review of building services concept — MVHR, heating, DHW
- Identification of potential compliance issues and recommended actions
- Preliminary assessment report with certification checklist
- Up to two review rounds included for resolution of outstanding items
Stage 03
Pre-Construction Review
Before construction commences
Before construction begins, the complete design documentation package is submitted via the PHI certification platform — final drawings, product technical data for all energy-relevant components, and the complete PHPP calculation. After careful review and comparison with the energy balance, we confirm compliance or identify corrections required before work proceeds. This is the last stage at which design-level changes can be made without construction cost implications.
- Review of all final energy-relevant planning documents and drawings
- Verification of technical data for construction products — windows, insulation, MVHR, airtightness membranes
- Detailed review of the complete PHPP calculation
- Comparison of PHPP energy balance against certification criteria
- Identification of required corrections with clear guidance for resolution
- Confirmation of readiness to proceed to construction
Stage 04
Post-Construction Review
After construction is complete
Following completion of construction, any changes from the pre-construction submission are updated and verified. As-built evidence — including the airtightness test result, documentation of MVHR flow rate adjustment and commissioning, and the construction manager's declaration — is reviewed and confirmed against the certification criteria. Upon successful completion of all requirements, the certificate is issued.
- Review of as-built changes and updated PHPP calculation
- Verification of airtightness test result (blower door test to ISO 9972 Method 1)
- Review of MVHR commissioning documentation and flow rate adjustment records
- Review of construction manager's declaration
- Confirmation that all certification criteria have been met
- Issuance of the PHI certification certificate
- Delivery of supplementary documentation booklet with energy balance and characteristic values
Certification Standards
Which standard applies to your project
Passive House Classic · Plus · Premium
The full standard for new buildings. Three tiers distinguished by primary energy demand and renewable energy generation. The core criteria — heating demand ≤ 15 kWh/m²a and airtightness ≤ 0.6 ACH@50Pa — apply to all three.
- Classic: primary energy ≤ 60 kWh/m²a · no renewable generation requirement
- Plus: primary energy ≤ 45 kWh/m²a + renewable generation ≥ 60 kWh/m²a
- Premium: primary energy ≤ 30 kWh/m²a + renewable generation ≥ 120 kWh/m²a
EnerPHit
The retrofit standard for existing buildings. Criteria are relaxed to acknowledge that full thermal envelope continuity is rarely achievable in refurbishment — but the performance improvement is still substantial. Two compliance pathways: component-based or energy demand-based.
- Heating demand pathway: ≤ 25 kWh/m²a (climate-adjusted)
- Component pathway: compliance per element — wall, roof, floor, windows, airtightness
PHI Low Energy Building
An intermediate standard between EnerPHit and full Passive House. Designed for projects where the full standard is not feasible but significant, documented energy performance improvement is achievable. Suitable for complex refurbishments and constrained new-build sites.
- Heating demand ≤ 30 kWh/m²a
- Primary energy demand ≤ 75 kWh/m²a
- Airtightness ≤ 1.0 ACH@50Pa
Not Sure Which Standard?
The right pathway depends on building type, existing condition, project constraints, and client ambition. A feasibility assessment — reviewing the design or existing building against the criteria for each standard — is the starting point. Book a consultation and we'll confirm which pathway is appropriate before any commitment is made.
- New build → Passive House Classic / Plus / Premium
- Retrofit → EnerPHit or Low Energy Building
- Constrained site or budget → Low Energy Building
FAQ
Common questions
Is certification guaranteed if the design meets the criteria?
No — certification is awarded on the basis of demonstrated compliance through verified documentation and independent quality testing, not on the basis of design intent. A project that meets the criteria in PHPP may still fail certification if the as-built condition deviates from the design, if the airtightness target is not achieved, or if MVHR commissioning documentation is incomplete. The certification process is designed to identify and resolve these issues before they become irreversible — which is why the four-stage structure matters.
How long does the certification process take?
It depends on project complexity and the pace of the design and construction programme. The certification stages are tied to project milestones — Preliminary Review happens during design, Pre-Construction Review before construction commences, Post-Construction Review after completion. A straightforward residential project might move through the full process in six to twelve months; a complex commercial project or one with multiple review rounds will take longer. We work at the pace of the project.
What is required for the airtightness test?
The blower door test must be carried out to ISO 9972 Method 1 — with all intentional openings sealed, testing the building envelope as it will function in normal operation. The result must be ≤ 0.6 ACH @ 50 Pa (Passive House Classic) or ≤ 1.0 ACH @ 50 Pa (Low Energy Building). The test result and method documentation are submitted as part of the Post-Construction Review package. BEO is ATTMA accredited for both L1 and L2 testing and can carry out the test as part of or separately from the certification engagement.
Can certification proceed if there are deviations from the pre-construction design?
Yes — construction always produces some deviations from the design. At Post-Construction Review, changes are updated in the PHPP and the revised energy balance is assessed against the criteria. Provided the as-built condition still meets the criteria — after accounting for the actual airtightness result, as-built thermal bridge values, and any specification changes — certification can proceed. Significant deviations that take the project outside the criteria require design review and may require remediation before the certificate is issued.
Do you also provide the design consultancy, or only the certification?
Both — as separate engagements. Design consultancy covers PHPP modelling, envelope design, thermal bridge analysis, MVHR coordination, and documentation support throughout the project. Certification is the independent quality assurance review. Many clients engage us for both; some have their own Passive House designer and engage us for certification only. See our Passive House Design consultancy service for the full design scope.
BEO Buildingscience - Passive House Certification and Design
BEO Buildingscience - Passive House Certification and Design
BEO Buildingscience - Passive House Certification and Design
BEO Buildingscience - Passive House Certification and Design
BEO Buildingscience - Passive House Certification and Design
BEO Buildingscience - Passive House Certification and Design