What a Building Biologist Sees in Your Home That a Regular Inspector Misses
By Lisa Waayer — Naturopath, Building Biologist & Low Tox Coach | ANTA & ASBB member
Short on energy? Here's the essence: A standard building inspection asks, “Is this structure sound and compliant?” A building biology assessment asks a different question: “Is this home affecting the health of the people inside it?” Moisture behaviour, hidden mould indicators, ventilation, air quality and chemical exposures all sit outside a conventional inspector's brief. If someone in your household is unwell and the house is a suspect, you need the second kind of assessment – ideally from someone who also understands the health side, which is where my dual training comes in.
Why did our building inspection come back clear?
Because it answered the question it was designed to answer: is the structure sound, safe and compliant? Whether anything in the building is contributing to a person's symptoms was never on the checklist, and the tools and time allocated to a standard inspection aren't built to assess it.
This comes up constantly – usually from a family member who organised an inspection, received a reassuring report, and is now more confused than before. The house passed. So why is someone still sick in it?
This isn't a criticism of building inspectors. It's a boundary of scope. The problem is that families rarely know the boundary exists – so a clean report quietly closes a line of inquiry that was never actually investigated.
What does a building biologist look for?
Water history, hidden moisture in concealed spaces, ventilation and condensation behaviour, bedroom air quality, and chemical load – all interpreted against the health of the people living there. It's the same house, read with a different set of questions.
When I assess a home, I'm reading it through two lenses at once – building biologist and health practitioner – and the questions change accordingly:
Where has water been, and where does it go? Not just active leaks, but history: past floods, old repairs, rising damp, the slope of the land, gutters and downpipes, shower recesses that have quietly failed. Water damage from years ago can still matter today.
What's happening where nobody looks? Subfloors, roof cavities, wall voids, behind wardrobes on cold external walls, under sinks, inside window frames. The significant findings in my work are almost never in plain sight – homes involved often look immaculate.
How does this house breathe? Ventilation and condensation patterns determine whether everyday moisture (showers, cooking, breathing) leaves the house or feeds growth inside it. Modern sealed homes and older under-ventilated ones fail this in different ways.
What are the occupants breathing all night? The bedroom gets special attention – you spend a third of your life there, immobile, breathing whatever it holds. Air quality, damp indicators, bedding environment and nearby moisture sources all matter.
What's the chemical load? Cleaning products, fragrances, recent renovation materials and furnishings that off-gas. Rarely the whole story, but often an unnecessary extra burden on someone already unwell.
And critically: who is sick, with what, and where do they spend time? This is what my naturopathic training adds. Symptoms are assessment data. A fatigue-and-fog picture sends me looking in different places than a wheeze-at-night picture. A building assessed without reference to the occupants' health is a building half-assessed.
The guide I wish I'd had
I came to this work through my own illness in a water-damaged home – which means I remember precisely what it's like on your side of this: holding a reassuring report in one hand and a sick family member in the other, wondering whether to trust the paperwork or the person. Trust the person. Then get the right kind of assessment, so the paperwork and the person finally agree.
How can I help someone whose home might be making them sick?
Arrange one assessment designed around health, carried out by someone who can also interpret what the findings mean for that person's recovery. Findings without clinical interpretation create anxiety; interpretation without findings creates guesswork. You need both together.
If you're the one booking inspections and holding the logistics while someone you love is unwell – the practical step is simpler than the last few months have felt. You don't need to arrive with a theory. You just need the house looked at properly, once, by someone who can read both halves of the picture.
Book an assessment and I'll look at your home the way it hasn't been looked at yet – thoroughly, calmly, and with the health of the people inside it as the entire point.
Frequently Asked Questions
What's the difference between a building inspection and a building biology assessment?
A building inspection assesses structure, safety and compliance – typically for a purchase or defect dispute. A building biology assessment examines health-relevant factors: moisture and mould indicators, ventilation, air quality and chemical exposures, interpreted in light of the occupants' symptoms.
Our building and pest report was clear. Could there still be a problem?
Yes. Health-relevant issues – hidden damp, poor ventilation, air quality problems – sit largely outside that report's scope and standard methods, so a clear report doesn't rule them out.
What happens during your assessment?
A detailed walkthrough of the home including concealed spaces where accessible, moisture and environmental investigation, a discussion of the household's health picture, and a written report with prioritised, practical recommendations – sequenced so you're not overwhelmed.
Do you find problems in clean, well-kept homes?
Frequently. The issues that affect health are usually invisible from the living spaces – cleanliness and hidden moisture are unrelated. No judgement is ever part of my assessments.
We rent – is this still worth doing?
Yes. Documented independent findings strengthen requests to landlords considerably, and many meaningful improvements are within a tenant's control regardless.