How PHI calculates eligibility for Passive House Plus and Premium certifications seems to be unclear, even to some experienced Passive House designers. There are many factors that impact the amount of energy generated by a specific renewable energy system on a day-to-day basis. But none of that matters for PH Plus or Premium certification. It’s about Primary Energy Renewable. And what is PER? It is simply new renewable annual generation potential divided by the footprint of the building thermal envelope.
What we’re used to seeing: rooftop PV generating energy for the certified building. But it’s not the only way to win Passive House Plus or Premium designation. Pictured: Kahika Tōtara Passive House Premium, Christchurch. Image © 2025 Ethos Homes Ltd
Your client can literally install PV panels in Niue and use them for certification of their Passive House Premium building in Invercargill. For the purposes of certification, you simply need to provide evidence of new renewable generation, paid for and owned by the developer/owner of the building being certified.
Sometimes I catch bits of complicated conversations on social media about batteries and exporting to the grid and storage and EV charging, in relation to the higher Passive House certifications. All that is awesome and those things have large economic impacts.
But Passive House Plus and Premium designations are about getting to a future fully-renewable society. They are set up so as to not penalise any single location or favour one sort of renewable generation over another. Using the footprint of the thermal envelope allows multi-storey buildings to match single-storey ones for rooftop PV.
It’s also why the location where the new renewable generation is installed doesn’t matter for the purpose of certification (different locations obviously generate different levels of energy annually). Ideally the generation is connected to the grid to allow energy to be shared. Otherwise, excess summer energy is very often dumped, one way or another —I discussed that here.
PER is a genius metric by the way and I’m sad it’s not better understood and used. It is such a simple way to account for seasonal storage losses . Plus it quickly illustrates the large co-benefit of reducing heating demand, which occurs during low PV energy availability in winter.
Technical reading on PER is available at Passipedia
Note the following requirements about availability of the renewable energy generation:
“To be considered in the PHPP, a renewable energy generation system must be ready for use at the time the building certificate is issued. This applies both for systems on the building premises and for off-site installations. If necessary, the certifier may initially issue a “Classic” certificate which can later be converted to a higher class after completion.”
Also, “Buildings without connection to the power grid are treated exactly like buildings connected to the grid in the PHPP with regard to the primary energy demand and to take into account renewable energy generation. The battery capacity and utilisation percentage of the electricity generated are not taken into account.”
“3.2.9 Renewable energy
Criteria
Suitable proof of ownership for renewable energy generation systems (except for solar thermal systems) on the building plot, or off-site. Or if applicable, evidence relating to the percentage of ownership of the system as a whole. For systems which are off-site, this evidence must show that it is a newly constructed system, i.e. a system that was not put into operation before the start of construction of the building and belongs to the building owner or the (long-term) user (first time acquisition). If constructing or purchasing renewable energy generation systems is part of the business model of the building owner, only systems which are on-site may be accounted for.”