PHPP Version 9.6 has now been tested pursuant to ASHRAE 140

20 February 2019 by Jason Quinn

“PHPP Version 9.6 has now been tested pursuant to ASHRAE 140, which qualifies it as an acceptable energy modelling software under a variety of regulatory systems”


This means that PHPP could now be used for H1 verification via the modeling method for buildings with interesting glazing ratio’s or other non-standard features.

The issue will be that Section G1.6.3 in “NZS 4218:2009 Thermal Insulation – Housing and Small Buildings” was copied from the bigger building standard and requires that a minimum of three thermal zones be defined in the model. As PHPP uses a single thermal zone (which is sufficient in Passive Houses and centrally fully conditioned buildings) this guidance cannot be met. I believe that in order to make this more straightforward we will need to develop a general guidance letter for councils with BRANZ and ECCA cooperation that permits a single thermal zone.

Of course this assumes that the Passive House single zone approach is being met by the building design. This is almost always the case but as we develop bigger and more complicated Passive House designs we need to make sure that this remains the case.

It is still much easier to show compliance by showing your building meets the R-values tables for most Passive House designs but knowing that you could show code compliance via the modeling method using PHPP is a big time saver on more complicated projects (or ones with silly amounts of glass).

The full report is available on request.

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