Tag Archives: H1

Using PHPP for Building Code H1 Compliance

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PHPP has been identified as a suitable building energy modelling tool for use to comply with the Building Code clause H1 using Verification Method H1/VM1 since the 5th edition (2022.) In the 5th edition of H1/VM1, PHPP version 9, 2015, was specifically referenced.

In the 6th edition of H1/VM1 (2025), the reference to PHPP has been removed and there is the following more general statement about modelling software:

2.2.3 Modelling software
2.2.3.1 If the application for which the software is to be used has been documented according to the ANSI/ASHRAE Standard 140 procedure, then the method shall pass the ANSI/ASHRAE Standard 140 test...

PHPP v9 was validated using ANSI/ASHRAE Standard 140 in 2019 and the report is available for reference. [PDF 2.9 MB]

PHPP v10 is also deemed validated as the Passivhaus Institut (PHI) has confirmed that “the algorithms for the calculation of the useful heating and cooling demand, as they become relevant in the framework of the ASHRAE 140 validation, have not been changed deliberately from version 9.6. For verification, PHI rechecked all test cases and found that the agreement has indeed not deteriorated.” [PHI letter, 3 June 2022]

Therefore, PHPP v9 and v10 are both valid for use to comply with the Building Code clause H1 using Verification Method H1/VM1 edition 6.

Jason Quinn has published guidance on how to use PHPP for H1/VM1 on his website that you may wish to refer to.

Want to purchase PHPP? You can buy it from our online shop here.

PHPP 10 cover photo

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PHINZ Submits Response to Building Code H1 Changes – A Call for a Transformative Approach

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Te Tōpūtanga o te Whare Korou ki Aotearoa, Passive House Institute NZ (PHINZ) has voiced its concerns regarding the proposed changes to the Building Code’s insulation requirements (H1) in a recent submission to the Ministry of Business, Innovation and Employment (MBIE). PHINZ believes that the proposed changes, while well-intentioned, represent incrementalism and are a step in the wrong direction. Instead, PHINZ proposes an alternative approach that they believe is necessary to achieve the desired outcomes for New Zealand’s built environment.

Key points of PHINZ’s proposed alternative approach include:

  • Replacing the current prescriptive and calculation methods with a predictive modeling approach based on ISO 52016.
  • Shifting the focus from minimum R-values to minimum absolute thermal performance levels.
  • Adopting the caps from the Building for Climate Change document.
  • Allowing a transition period to the implementation of the first cap of 24 months.

Predictive Modeling Approach
PHINZ strongly supports the transition to a predictive modeling approach based on ISO 52016. This allows for a more accurate and flexible assessment of a building’s energy efficiency compared to the current prescriptive methods.

Minimum Absolute Thermal Performance Levels
Instead of relying solely on minimum R-values, PHINZ recommends shifting the focus to minimum absolute thermal performance levels. This means setting specific targets for the amount of energy a building is allowed to consume, rather than just specifying the thermal resistance of individual building elements. This approach encourages a more holistic view of building performance and promotes innovation in building design and construction.

Building for Climate Change Caps
PHINZ proposes adopting the caps from the Building for Climate Change document, which outlines a roadmap for reducing emissions from buildings in New Zealand. These caps would set progressively stricter limits on the energy consumption of new buildings, driving significant improvements in energy efficiency over time.

Transition Period
To allow the industry to adapt to these changes, PHINZ suggests a transition period of 24 months or more to the implementation of the first cap. This would give builders, designers, and manufacturers sufficient time to adjust their practices and product offerings, ensuring a smooth shift towards more energy-efficient buildings.

Conclusion
PHINZ believes that their alternative approach is crucial for improving the energy efficiency of buildings in New Zealand. They urge MBIE to give their feedback careful consideration before finalizing any decisions on the proposed changes.

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