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I wrote this wrap up as I sat on the Esplanade in Cairns, the Saturday morning after the conference finished, with my oat cappuccino and Far North Queensland sun to keep me company and now I’d love to share it with you all.

AIRAH IAQ 2026 was held between 31st August to 4th September in Cairns, Far North Queensland. It was a conference focussed on building science and HVAC design, with an overarching theme of humidity and dehumidification. It was a different crowd to what I am used to – mechanical engineers abounds and hardly any builders or architects, which was a shame. But it was an incredible conference, meeting Dr Joe Lstiburek was a hoot and I learned a lot about mechanical systems and indoor air!

It’s crazy to me, in both commercial and residential contexts, how much effort and expense goes into controlling this invisible stuff all around us (air) and all of the things it carries. How much of an impact air has on every part of a building. I am incredibly grateful to the entire AIRAH IAQ tech committee for a huge 5 days….

• Dr. Claire Bird, Affil.AIRAH (LITMAS)
• Brad Prezant, Affil.AIRAH (Prezant Environmental)
• Jeremy Stamkos, M.AIRAH (Restoration Industry Consultants)
• Derek Shearer, M.AIRAH (Chubb Fire & Security Australia)
• Sonia Holzheimer, M.AIRAH (STP Consultants)

Everything went without a hitch and that’s no small feat. Read on for my four main takeaways from this conference:

1. People need to breathe, walls do not.

I already knew this one, but this belief is SO pervasive. In a timely manner, a friend of mine who lives in Cairns even said that all the big windows in her house allowed it to “breathe” after dinner on the Friday night – but after 5 huge days, I didn’t have the brain space to explain… I’ll save that for another dinner 😄
When people say walls need to breathe, what they mean is walls need to dry. They are not the same thing but “breathing” implies air movement, which is what we don’t want through our walls. We want the outdoor air to stay out, and the indoor air to stay in, and the drying capacity to be optimised. And the reason we don’t want uncontrolled air moving through our walls into our homes is…

2. Fresh air does not necessarily equal outdoor air.

Outdoor air carries fine and ultra fine particulates, pollen, moisture, smells, dust, mould spores and during bushfire season – smoke. Opening the windows for “fresh air” doesn’t mean you’re actually getting fresh air. In Australia we live in a culture that celebrates outdoor living and it’s important to understand that air tightness does not take that away. Door and windows can still be opened at your will. Air tightness simply gives us the control over heat, cold, pollen and smoke when we want it instead of letting it creep through the walls.

3. Code compliance is the floor (or the flaw…) not the ceiling.

The mechanical game is as plagued by minimum compliance as the envelope game – in fact I think it’s worse. The minimum standards aren’t anywhere near good enough, but many people don’t want to spend a dollar more than they have to, and they believe that code compliance means “good enough”, but unfortunately this leads to poor outcomes for buildings and for the people inside.
4. The control layer order matters.

Every high-performance wall must maintain four continuous control layers in this priority sequence: Water -> Air -> Vapour -> Insulation. As mentioned above, water always comes first. Next is the air barrier. Air barrier continuity is paramount as air leakage carries up to 100 times more moisture into wall cavities than vapor diffusion. Next is the vapour layer and last is the insulation – and you only need the the three if you have insulation! Because insulation, and reduced heat flow, is what changes the drying capacity of our assemblies. As an industry we’ve been so focussed on energy efficiency and more and more insulation, that we have largely forgotten about water, air and vapour!

Above is a collage of my favourite photos from an amazing week in Cairns. Top – dinner with the AIRAH committee, delegates and speakers including Dr Joe Lstiburek. Middle L-R, Dr Joe and I at lunch, Sean Maxwell, Penny Trelau, Dr Joe and myself on day 5, the Cairns Esplanade. Bottom L-R Sonia Holzheimer, Marie Karekla, Julia Bassel, Penny Trelau and myself, the conference room from the rear, Dr Joe on stage.

What confuses me is that I can go to conference after conference, Passive House, Building Physics, Indoor Air Quality and more – all of which are flooded with solutions and so many people who really really care, yet the solutions we all talk about and advocate for just don’t spread far enough fast enough.

As Joe said, it’s got to hurt real bad before we accept that change is necessary. And buildings generally fail slowly, not quickly. The lessons are still coming here.

“It’s ok if our buildings get wet, but they have to be able to dry” – Dr Joe Lstiburek

It sounds basic – but by building our houses with more and more insulation and by using water sensitive materials like timber, ply and plasterboard, this means that the drying potential of our buildings MUST be taken care of as the first priority. Water, water, water.
If the drying potential of our buildings does not exceed the wetting potential, we are still learning.

The US and Canada went through a bunch of painful litigation over sick buildings, and the lawyers and insurance companies were the ultimate teachers. Are we litigious enough in Australia? Or do we just bury our mistakes so no one is held accountable and no one learns. Victoria has been through/is going through its own leaky building crisis, but is that on the record? No.

Well that’s a wrap on AIRAH IAQ 2026, I’ll be thinking about that one for a while.

Cheers!