Certification support, coordinated by your engineering partner.
We prepare the PHPP modelling, design and evidence and coordinate with your independent Passive House Certifier — so the formal certification runs smoothly, with one engineering point of responsibility.
Retrofit IQ provides the engineering, modelling and design. The formal Passive House and EnerPHit certification is carried out by an independent, accredited Passive House Certifier. We coordinate with the appointed certifier on your behalf throughout the project.
What is certification support?
Passive House and EnerPHit certification is awarded by an independent, accredited Passive House Certifier — not by us. Our role is to make that process straightforward: we assemble and quality-check the technical evidence and coordinate with the certifier on your behalf.
That means accurate PHPP, well-documented details, airtightness and ventilation evidence, and clear responses to certifier queries — all handled by your engineering and design partner.
- PHPP model preparation and quality checks
- Design details and construction evidence
- Airtightness test and MVHR commissioning evidence
- Document collation for the certifier
- Responding to certifier queries and comments
- Keeping the project on track to certification
A clear, coordinated route to certification
From evidence to certificate
We confirm the target standard and exactly what the appointed certifier will need.
We assemble PHPP, details, airtightness and ventilation evidence to certifier standard.
We liaise with the independent certifier and manage the submission on your behalf.
We respond to comments with engineering clarity to keep the process moving.
The independent certifier issues the formal certificate; we keep your records in order.
The engineering payoff
We coordinate the certifier so you don't have to project-manage the paperwork.
Certifier-ready evidence first time reduces back-and-forth.
Evidence grounded in building physics and PHPP, not assumptions.
A complete, well-organised certification record for your project.
The engineering & design partner — not the certifier
Retrofit IQ provides the engineering, modelling and design, led by a Certified Passive House Designer. The formal certification is always awarded by an independent, accredited Passive House Certifier. We coordinate with them on your behalf — so you get rigorous engineering and a smooth certification, with one point of responsibility.
Part of one engineering-led workflow
Our services connect into a single, engineering-led journey — measured diagnosis, professional building physics modelling and engineering calculations, and a designed retrofit. They are not separate offers; they are stages of the same process.
Measured diagnosis of heat loss, damp, mould, air leakage and ventilation — the evidence base for everything that follows.
ExploreProfessional building physics modelling and engineering calculations to predict how your construction will perform before any work begins.
ExploreIndependent assessment of whether your building fabric is ready for an efficient, low-running-cost heat pump.
ExploreUltra-low-energy design to the Passive House standard, engineered from first principles.
ExploreAccurate Passive House Planning Package modelling, built and interpreted by a Certified Passive House Designer.
ExploreThe Passive House retrofit standard — a staged, engineering-led path to a high-performance existing home.
ExplorePassive House Certification Support — FAQs
Does Retrofit IQ issue the certificate?
No — and this is important. The formal Passive House or EnerPHit certificate is issued only by an independent, accredited Passive House Certifier. Retrofit IQ is the engineering and design partner that prepares the evidence and coordinates with that certifier.
Can you work with our chosen certifier?
Yes. We coordinate with the appointed independent certifier, whoever that is, and tailor the evidence to their requirements.
What if we don't have a certifier yet?
We can advise on the process and the evidence needed, and coordinate once an independent certifier is appointed. The certification decision always rests with them.
Is certification support available for EnerPHit too?
Yes — for both Passive House (new build) and EnerPHit (retrofit) projects.
Make certification the easy part.
Let your engineering partner prepare the evidence and coordinate your independent certifier.