Mould Assessments Across New Zealand
Qualified mycologists and occupational hygienists assessing properties to international standards — nationwide
Comprehensive Mould Assessment, Available NZ-Wide
A professional mould assessment goes beyond visual inspection. Our McCrone-certified mycologists and MAIOH-accredited occupational hygienists use a systematic, evidence-based approach combining air sampling, surface sampling, moisture measurement, and environmental monitoring to evaluate mould conditions in your property. Results are classified to ANSI/IICRC S520 (2025) standards and reported with clear, actionable recommendations.
We deliver on-site assessments directly across the central North Island, and coordinate nationwide coverage through our network of trusted mould assessors in Auckland, Wellington, Christchurch, Dunedin and beyond. Every assessment — whoever attends — is backed by analysis from our own Hamilton laboratory.
Book Your AssessmentWhat a Mould Assessment Costs
No two properties are the same, so the fee depends on the distance travelled and the size and complexity of the site. As a guide:
$800–$1,200 ex. GST for a typical residential assessment by a senior occupational hygienist and mycologist — covering the on-site visit, sampling, laboratory analysis and a full written report.
Larger or more complex investigations — such as mycotoxin exposure assessments, insurance claims, tenancy disputes, or matters likely to head to legal action — are scoped individually. Tell us what you need the assessment to establish, and we'll structure the investigation around your budget and requirements. Get in touch to discuss your situation.
What a Scaada Mould Assessment Includes
Unlike a single mould test, an assessment is a structured on-site investigation by specialists who are both trained mycologists and occupational hygienists — so you learn what mould is present, how severe it is, and where the moisture feeding it is coming from.
1 · Site inspection
A walk-through documenting visible mould, water-damage indicators and ventilation issues — setting the sampling strategy for your property.
2 · Air & surface sampling
Spore-trap cassettes measure airborne spores and tape lifts capture growth on surfaces, with an outdoor reference sample taken the same day for comparison.
3 · Moisture mapping
Non-invasive moisture, temperature and humidity readings locate the water source driving growth — not just the mould itself.
4 · Laboratory report
McCrone-certified analysis to ASTM methods, returned as a signed report with IICRC S520 condition ratings and clear next steps.
How We Sample — and Why It's Done This Way
An assessment combines three measurement methods. Together they reveal not just what mould is present, but whether it is actively growing and where the moisture feeding it is coming from.
Air sampling
A calibrated pump draws air through spore-trap cassettes at 15 litres per minute, capturing spores and fungal fragments by inertial impaction. Indoor results are only meaningful against an outdoor baseline — so every assessment includes an outdoor reference sample taken the same day. Analysis follows ASTM D7391-20, quantifying structures per cubic metre of air and identifying the genera present, with ACGIH bioaerosol principles applied to interpret them.
Surface sampling
The tape-lift technique collects a 4 cm² sample directly from affected surfaces, preserving mould spores and hyphae in their natural arrangement. Laboratory analysis following ASTM D7658-17 identifies the genera, quantifies spore density per square centimetre, and — critically — distinguishes active growth from settled spores blown in from elsewhere. Concerned about black mould? This is the definitive way to confirm whether dark growth is Stachybotrys chartarum or one of many look-alikes.
Moisture & environmental measurement
Mould is a symptom of moisture. Using a professional FLIR moisture meter we take non-invasive readings across building materials — timber framing should sit below 15% moisture content — alongside temperature and relative humidity. NZS 4303:1990 recommends indoor relative humidity below 60%; readings consistently above that support germination even where surfaces look dry. Combined with the sampling results, this builds a moisture map pointing to the actual source: a roof leak, plumbing failure, condensation, rising damp or weather-tightness fault.
Standards & Methodology We Follow
Our assessments are conducted to internationally recognised standards, ensuring results are consistent, reproducible, and defensible for insurance, legal, and health purposes.
- ANSI/IICRC S520 (2025) — Standard for Professional Mould Remediation. Provides the condition rating framework (Condition 1, 2, 3) used to classify mould contamination and determine appropriate remediation scope
- NZS 4303:1990 — New Zealand Standard for Ventilation for Acceptable Indoor Air Quality. Sets the benchmark for indoor humidity levels and ventilation requirements
- ASTM D7658-17 — Standard Test Method for Direct Examination of Fungal Structures on Building Materials. Our methodology for surface (tape lift) sample analysis
- ASTM D7391-20 — Standard Test Method for Categorisation and Quantification of Airborne Fungal Structures. Our methodology for air sample analysis
- ACGIH Bioaerosol Assessment — American Conference of Governmental Industrial Hygienists guidance for interpreting indoor air sampling results in the context of occupant health
These standards ensure our findings stand up to scrutiny — whether you need results for peace of mind, a remediation contractor, your insurer, or a legal proceeding.
Reading Your Results: the IICRC S520 Conditions
Every sampled area is classified against the IICRC S520 condition rating system — a standardised way to express how serious the contamination is and what, if anything, needs to happen next.
Condition 1 · Normal
Mould levels typical of a healthy indoor environment, with no water damage or humidity issue. No remediation required.
Condition 2 · Settled spores
Elevated spores settled from contamination elsewhere or outdoors. Cleaning advised; investigate the source.
Condition 3 · Active growth
Confirmed colonisation on building materials. Professional remediation recommended, scoped to the genera and extent.
Your report explains which condition applies to each area in plain language — with the species identified, the indoor-versus-outdoor comparison, the presence of any water-damage indicator species, and specific recommendations for your property.
Ready to find out what you're actually dealing with?
Book an on-site assessment, or send us a sample from anywhere in New Zealand. Either way you get a McCrone-certified report with IICRC S520 condition ratings and clear next steps.
Mould Assessments Anywhere in New Zealand
Wherever your property is, we can arrange a qualified assessment — every one backed by analysis from our own Hamilton laboratory.
Direct service · central North Island
Our own team carries out on-site assessments across the Waikato, Bay of Plenty, Auckland and surrounding regions, with our own assessors and equipment.
National assessor network · everywhere else
For Northland, Wellington, Manawatū-Whanganui, Hawke's Bay, Taranaki, Nelson, Marlborough, Canterbury, Otago, Southland and the West Coast, we coordinate with independent assessors we know and trust. They follow our sampling protocol and return samples to our Hamilton lab — so you receive the same Scaada NZ report regardless of who attends.
Lab-only · send us the samples
Qualified assessors, builders and remediation contractors can work with us on a lab-only basis: request a kit, follow the chain-of-custody, and courier the samples overnight.
Not sure which fits your situation? Get in touch and we'll match you to the right option for your region.
Why a Professional Assessment Beats a DIY Kit
DIY mould kits have real limits that can send you down the wrong path:
- Misidentification — without trained microscopy, look-alike genera with very different health risks are easily confused
- An incomplete picture — a single swab says nothing about hidden growth, airborne levels, or the moisture driving it
- No standing — DIY results aren't accepted by insurers and carry no professional accountability
A professional assessment gives you objective, defensible evidence — the basis you, your insurer, your landlord or your GP need to act with confidence. It's worth booking one when symptoms are present, the affected area is larger than 1 m², mould keeps returning after cleaning, you're buying or selling, or there's an insurance or legal angle.
Who Carries Out Your Assessment
Your samples are handled by qualified specialists — trained mycologists who are also occupational hygienists, so results are interpreted in a health context, not just a laboratory one.
Patrick Crawford
Principal Mycologist & Laboratory Director
McCrone Research Institute Certified Mycologist with 17 years' laboratory experience and ISO 17025 technical-assessor standing for mould. Full Member, AIOH (MAIOH).
Holly Bredin-Grey
Mould Analyst & Occupational Hygienist
McCrone Research Institute-trained analyst and qualified Occupational Hygienist with a Graduate Certificate in Occupational Hygiene. Member, AIOH (MAIOH).
Mould Assessment FAQ
What does a professional mould assessment involve?
A professional mould assessment includes a visual inspection of your property, air sampling using calibrated spore trap cassettes, surface sampling via tape lifts, moisture content readings of building materials, and temperature and humidity measurement. All samples are analysed in our laboratory using ASTM methods, and you receive a detailed report with IICRC S520 condition ratings and clear recommendations.
How long does a mould assessment take?
The on-site assessment typically takes 1 to 2 hours depending on property size and the number of areas requiring sampling. Laboratory analysis is completed within 3 to 5 business days, with priority turnaround available for urgent cases. You'll receive your full report with results and recommendations as soon as analysis is complete.
What is the difference between a mould assessment and a mould test?
A mould test analyses a specific sample in the laboratory to identify and quantify mould genera. A mould assessment is a comprehensive on-site evaluation that includes multiple tests, moisture readings, environmental measurement, and professional interpretation — providing a complete picture of mould conditions in your property with actionable recommendations. Think of a test as one data point; an assessment is the full investigation.
What qualifications should a mould assessor have?
A qualified mould assessor should hold recognised mycology training (such as McCrone Research Institute certification), membership of a professional body such as the Australian Institute of Occupational Hygienists (AIOH), and working knowledge of ANSI/IICRC S520 remediation standards. Be cautious of providers without verifiable credentials — mould assessment is an unregulated field in New Zealand, and the quality of results varies significantly.
Do I need a professional assessment or can I test mould myself?
For small areas of visible mould where you simply want to identify the species, a DIY tape lift kit sent to our laboratory may be sufficient — contact us and we'll send one with instructions. However, professional assessment is recommended when health symptoms are present, the affected area is larger than 1 m², mould keeps returning, you are buying or selling a property, or the situation involves insurance or legal proceedings.
Do you do mould assessments outside the central North Island?
Yes. Our own team carries out on-site assessments across the Waikato, Bay of Plenty, Auckland and surrounding regions. For properties further afield — Wellington, Christchurch, Dunedin, Northland and everywhere in between — we coordinate with a network of trusted independent mould assessors who follow our sampling protocol and send samples back to our Hamilton laboratory for analysis. The report you receive is the same regardless of which assessor attends, and laboratory-only sample submission is available from anywhere in NZ.
Book Your Mould Assessment
Tell us about your property and we'll recommend the right assessment for your situation.