The Healthy Home Movement in Australia

Years before healthy building materials were something Australian builders talked about, Zara D’Cotta was quietly building the movement, and I’m proud to say I got in early. This week I was back in her Healthy Building Materials Mastermind live session, a room full of builders and designers from across Australia comparing notes on paints, membranes, insulation and indoor air quality, and it struck me how far this conversation has come. This post is partly an update on where the movement is at, and partly an unashamed plug for the work Zara is doing, because it deserves a much bigger audience.

Who is Zara D’Cotta, and what is The Healthy Home?

The Healthy Home is Zara’s education and consultancy platform focused on healthy building materials, building biology and indoor environmental quality. Her origin story is the one a lot of people in this space share: she was living in a home and started reacting to the building materials around her. When she went looking for safer products, she found a paint carrying a trusted logo and “low VOC, ecological” labelling that still contained an antimicrobial with no specific ingredient disclosure. The labels weren’t answering the actual question: what is in this product?

That question became her standard, and it’s the single most useful filter I’ve taken from her work: full ingredient transparency beats certification labels. Given the choice between a product with no certification but a fully disclosed ingredient list, and a certified product that won’t tell you what’s in it, take the transparent one every time. No certification scheme currently requires both full ingredient transparency and emissions testing, and the Red List has assessed only around 10 per cent of chemicals in commercial use. A label can only ever tell you what someone checked for.

What builders in this space are learning

A taste of the session, because this is the level the conversation now operates at:

Paint is a bigger deal than you think. Acrylic paints are now recognised as one of the largest sources of environmental microplastic emissions globally; one modelling study put paint at around 37 per cent of plastic microparticles. The alternatives are old technology done well: lime washes, clay paints, and mineral silicate paints like KEIM, a Bavarian brand more than a century old that’s been used on the Raffles Hotel in Singapore and is currently the only paint brand publishing vapour permeability data. The trade-off is real, sometimes more coats, more maintenance, but lime can even self-heal fine cracks.

“Low VOC” is not the same as safe. The origin and toxicity of the compounds matter more than the number. Natural VOCs from linseed or tung oil can read high on a meter and be benign, while the hidden risk is semi-VOCs, the persistent compounds like antimicrobials and plasticisers that a “low VOC” label doesn’t capture at all. The transparency benchmark in the room was Livos, a German brand 35 years in, publishing every raw material, and testing at zero semi-VOC emissions at both 3 and 28 days after application.

Whole-of-system thinking is the point. As one builder in the group put it: you can do all this great work on a vapour-permeable wall system and then a latex paint on the finished wall means the whole assembly can’t breathe. Materials aren’t ingredients in isolation, they’re a system, which is exactly how builders should already be thinking.

The momentum is institutional now. NCC 2025 embeds indoor air quality and moisture provisions more deeply. Evidence-based mould remediation has been adopted as an Australian standard. Australia’s first low-EMF new build site testing happened the same day as our session. And one of the builders in the group has been featured in Domain for wood fibre insulation and vapour-permeable membranes, framed as adding resale value. When the mainstream property press is presenting healthy materials as a value-add, the movement has left the fringe.

How I embed this in a building business

My contribution to the session was the practical end, because knowing about healthy materials and actually delivering them through a building company are different problems. Three things I’ve learned:

1. Put healthy selections into your price book and estimating tools. If the healthy option lives in your estimating system with a price against it, it gets specified. If it lives in your head as a good intention, it gets value-managed out the first time a budget tightens. This is a systems problem, not a virtue problem.
2. Treat it as a cultural shift, and narrate the why. Your team and your subbies will only carry this standard if they understand the reasoning, so talk it through constantly. When a subbie can explain to a client why the membrane matters, the message gets reinforced from every direction.
3. Decide your non-negotiables. Some choices are baseline on every job we do. Others get weighed openly with the client against budget. Both are fine; what fails is having no line at all.

Where Zara is taking it

The exciting part is what’s next. Zara is working on turning the mastermind’s accumulated knowledge into a living, searchable database, so a builder mid-project can look up “in-floor heating” or a specific paint system and get the collective, field-tested experience of the group rather than a marketing sheet. And the demand signal is already flowing upstream: builders in this program have started asking suppliers questions the suppliers can’t answer. One manufacturer’s technical manager contacted Zara the same day a builder submitted a materials assessment, asking for help, and at least one major supplier is now seriously considering moving to full ingredient transparency because of it.

That’s how an industry actually changes. Not regulation first, but builders asking better questions in enough volume that transparency becomes commercially safer than silence.

Healthy materials sit at the heart of my own certified passive house build, and the philosophy runs right through the Dream Home Book: a home should make the people in it healthier, not slowly do the opposite. If you’re a builder or designer who wants to get serious about this, Zara’s mastermind is where I’d point you. Getting in early on this one is still possible. Just not for much longer.