16 June 2022 by Jason Quinn

PHPP10 is the next iteration in Passive House design tools from PHI. This introduces huge changes for the work of high-performance building designers in New Zealand (and Australia). Check out the extensive release notes from PHI here (yes the Germans had it last year, the English version has only just been released).

Including the Southern Hemisphere is the most obvious and fundamental change to the internal setup of PHPP. This is very welcome. Time-consuming and error-prone mirroring of the building about the equator is no longer needed. What a big relief for my team of certifiers as it seemed like any PH designer not using designPH had major issues for their first few projects.

This change creates subtle improvements throughout PHPP, doing away with what we had to live with as acceptable errors in PHPP9 etc. For instance, we used to shift the climate six months, which was fine for the solar energy gains. However the heating demand was calculated over fewer days, because February only has 28 of them. Having three more days makes for more accurate calculation of heating demand. These changes are small (and this issue  was known) but it’s important that folks designing in PHPP understand this change.

Two more improvements we’re happy about:

  1. Ground sheet has been improved so it’s more accurate for temperate climates (I’ll  discuss this in more detail in a future post).
  2. fRSI is now calculated using an internal moisture balance. This more accurate estimate allows more window/detail choices than were previously allowed.

The Sustainable Engineering team will be shifting to PHPP10 for all of our work over the next few months (and almost immediately for any new projects targeting Passive House certification). Don’t delay upgrading to PHPP10 for any new projects that are targeting PHI certification.

Welcome to the PHPP10 – What’s new for New Zealand 
Webinar conducted last August 29, 2022

Practical, applied training for novice Passive House designers: brand new from SEL Read more.