Green Star Airtightness Testing Services | ATTMA Level 2 Certified – BEO Buildingscience
Why Airtightness Matters for Green Star Projects
Green Star used to treat airtightness like a bonus round—now it’s table stakes. If you’re aiming for a Green Star rating in New Zealand or Australia, airtightness isn’t just a nice-to-have anymore. It’s mandatory.
Why? Because airtightness is the secret weapon behind predictable energy performance, thermal comfort, and making sure all those fancy HVAC systems aren’t wasting their breath (literally). And if your envelope is leaky? You’ll never get close to net zero, no matter how many solar panels you stick on the roof.
We’ve tested hundreds of buildings that look perfect—until the fan goes on. Then the truth leaks out.
Our ATTMA Level 2 Airtightness Testing Process
If you’re after professional airtightness testing that ticks every Green Star box, we’ve got you. Our team is ATTMA Level 2 certified, which means we’re qualified to test large commercial buildings, multi-unit dwellings, and anything in between.
We use blower door testing to pressurise or depressurise your building and measure leakage at 50 Pascals (the standard pressure difference). That part is science. The rest is experience—knowing where to look, how to prepare, and what’s likely to cause a fail.
Here’s what you get:
A full test plan based on your building type
On-site testing using calibrated equipment
A final report compliant with AS/NZS ISO 9972:2015 and ATTMA TSL2
Clear next steps if anything needs fixing
Oh, and we don’t just chuck numbers in a spreadsheet and wish you luck. We walk you through what the result means and whether it’s fit for Green Star submission.
Meeting Green Star Airtightness Requirements in NZ and Australia
Here’s the short version:
Yes, you have to test.
The latest versions of Green Star Buildings (in both NZ and Australia) require airtightness testing of the entire conditioned envelope. No cherry-picking. If you can’t test it all at once, you need to do sectional testing and calculate a weighted average.
Target benchmarks vary:
2.0 m3/hr/m2 for mechanically ventilated offices
1.0 m3/hr/m2 for dwellings with MVHR or mixed-mode
5.0 m3/hr/m2 for naturally ventilated dwellings
These aren’t just numbers. They’re pass/fail lines.
Testing has to be done by someone qualified. That’s where ATTMA Level 2 certification comes in.
Common Challenges in Green Star Airtightness Testing – and How We Solve Them
Let’s be honest. Most commercial buildings in our part of the world weren’t designed with airtightness in mind.
They have:
Service risers that go straight from the basement to the roof.
Stairwells with no separation between zones.
Plant rooms that are technically inside the envelope but open to the elements with louvres.
None of this is a dealbreaker, but it does make things... complicated. You can’t fix these issues on test day. But you can design around them—if you involve a professional tester early.
We help you:
Define your test boundary early in the design phase
Identify problem areas before they cost you Green Star points
Choose the right test method based on your building type and layout
Design Support for Airtightness: From Planning to Certification
We don’t just show up with a fan and a clipboard. Our best clients bring us in at the design stage—because that’s when we can save you the most money, stress, and finger-pointing later.
We help you:
Set airtightness targets that align with your HVAC and energy modelling
Detail penetrations, junctions, and interfaces to actually perform as modelled
Coordinate airtightness strategy with Passive House, Homestar, NABERS, or LEED pathways
Because airtightness isn’t a spec line item. It’s a design philosophy.
The problems with typologies and test methods - commercial buildings
On paper, a full-building airtightness test sounds simple. In reality? Not so much. Commercial buildings often include a messy mix of conditioned zones, unconditioned buffer areas (like car parks or delivery bays), and half-sealed service rooms with louvres to the outside. This means your thermal envelope isn’t always clear—and your airtightness boundary gets complicated fast. In these videos, we cover:
✔️ What counts as part of the envelope (and what doesn’t)
✔️ Why service rooms and risers throw off test results
✔️ Common traps with integrated carparks and ventilated spaces
✔️ Why early involvement of an airtightness professional is essential
✔️ How to set up for a useful test—even when the design isn’t airtight-friendly
💡 Designers: just because it looks “inside” on the drawing, doesn’t mean it performs like it. 🎬 Don’t miss the rest of the Typology Series: 🏠 Standalone Homes 🚪 Attached Garages 🏢 Apartments 🧱 Townhouses 🏬 Commercial Zones & Subsections
📌 Best for: Architects | Builders | Green Star Consultants | Passive House Designers | Building Services Engineers
Compliance Documentation for Green Star Buildings
Testing without documentation? Might as well not test.
We provide:
Test certificates and reports that meet Green Star submission standards
Photos and diagrams showing test boundary, fan setup, and temporary sealing
Clear summaries of results and air permeability figures, calculated correctly (no fudging)
Need to test in sections? We explain how the area-weighted result was calculated. Need to explain why the stairwell was sealed off? We document that too.
Basically, we make sure your airtightness test doesn’t cause submission delays.
Why Choose BEO Buildingscience for Green Star Airtightness Testing?
Because we actually give a damn. And because we know what we’re doing.
Certified to ATTMA Level 2
Trusted by architects, engineers, and contractors across NZ and Australia
Experienced in testing everything from Passive Houses to giant commercial slabs
After 15+ years doing this, we’ve seen what happens when airtightness is an afterthought. It’s not pretty. But it’s preventable.
We’re the ones who:
Show up prepared
Don’t waste your time
Give you clear, honest feedback
And we actually explain what the numbers mean. In English.