What is PHPP in Passive House design?
Behind every Passive House is a model.
Not just a concept —
but a detailed calculation of how the building will actually perform.
That model is created using PHPP.
And while most homeowners never see it,
it’s one of the most important parts of the process.
What does PHPP stand for?
PHPP stands for Passive House Planning Package.
It is a design and verification tool used to model the performance of a building before it is built.
Developed by the Passive House Institute,
PHPP is used worldwide to design and certify Passive House projects.
What does PHPP actually do?
PHPP calculates how a building will behave in real conditions.
It takes into account:
- climate and location
- building orientation
- insulation levels
- window performance
- airtightness
- ventilation systems
- internal heat gains
From this, it predicts:
- heating and cooling demand
- total energy use
- indoor comfort levels
👉 long before construction begins
Why is PHPP important?
Without PHPP, Passive House would be a concept.
With PHPP, it becomes predictable.
It allows the design team to:
- test decisions early
- adjust the building before construction
- avoid performance gaps
- ensure the final result meets strict targets
Instead of guessing how a building will perform,
PHPP makes it measurable.
Is PHPP the same as NatHERS modelling?
No.
Both use modelling, but they serve different purposes.
NatHERS is used to assign a star rating based on predicted performance.
PHPP is used to design and refine the building
to meet strict performance targets.
👉 It’s not just an assessment tool —
it’s part of the design process itself.
Do homeowners need to understand PHPP?
Not in detail.
PHPP is a technical tool used by designers and consultants.
What matters for homeowners is what it delivers:
- a building that performs as intended
- consistent comfort
- reduced energy use
PHPP sits behind the scenes,
ensuring those outcomes are achieved.
When is PHPP used?
PHPP is used from the early design stages.
The earlier it is introduced,
the more effective it becomes.
It continues through:
- concept design
- detailed design
- verification before construction
- final certification
Trying to apply it later in the process
limits its effectiveness — and can increase costs.
Final thoughts
PHPP is what turns Passive House from an idea
into a measurable, reliable outcome.
It doesn’t replace design —
it supports it.
And it ensures that what is designed
is what actually gets built.
