Blower Door Testing
Ensure your building is energy efficient, airtight, and compliant with Green Star, NatHERS, or Passivhaus requirements.
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Measuring Building Airtightness for Energy Efficiency and Compliance
At Green Choice Consulting, we provide professional blower door testing services to clients across Perth. This diagnostic service helps builders, architects, and property owners measure how much air is leaking through the building envelope.
Airtightness is a critical factor in achieving energy efficiency, thermal comfort, and compliance with performance standards such as NatHERS, Green Star, or Passive House.
Whether you’re working on a new build, major renovation, or a high-performance residential project, a blower door test offers valuable insights into the integrity of your construction and opportunities for improvement.
What Is Blower Door Testing?
Blower door testing is a recognised method used to evaluate the airtightness of a building.
A specialised fan (blower door fan) is temporarily installed in an external door or window, and the building is pressurised or depressurised to measure the amount of air that enters or escapes through unsealed areas.
The rate of airflow required to maintain a pressure difference indicates how leaky the building envelope is.
Results are typically presented in terms of:
- Air Changes per Hour at 50 Pascals (ACH50) – how many times the air inside the building is replaced per hour under test conditions
- Air leakage rate in cubic metres per hour (m³/h) – the total volume of air leaking into or out of the building
These metrics help project teams assess whether the building meets performance benchmarks and highlight areas where sealing improvements are needed.
Blower Door Test Requirements
There is no single airtightness target that applies to all buildings, but there are several well-established benchmarks:
Passive House standard: ≤ 0.6 ACH50
Required for certification under the Passive House Institute. This is one of the most stringent airtightness requirements globally.
Green Star or high-performance buildings:
Typically ≤ 5 ACH50 in residential buildings, or ≤ 10 m³/hr/m² of envelope area for commercial buildings. These levels support energy efficiency without compromising ventilation design.
New Australian homes (non-certified):
Best practice suggests ≤ 5–7 ACH50. This helps reduce heating and cooling demand while maintaining indoor air quality when ventilation is managed appropriately.
Typical older homes (untested):
Often test at 10–20+ ACH50, indicating substantial uncontrolled air leaks.
During the testing process, we provide a clear explanation of how your building’s results compare to these benchmarks and whether adjustments could improve energy outcomes or certification readiness.
Why Airtightness Matters
Airtightness is a fundamental component of a well-performing building. Air that escapes through unsealed gaps bypasses insulation, reduces heating and cooling efficiency, and introduces draughts and dust.
Excessive leakage can also increase the risk of moisture problems, such as condensation forming inside wall cavities, potentially leading to structural issues or mould growth over time.
Good airtightness contributes to:
- Energy savings – reducing the load on heating and cooling systems
- Thermal comfort – minimising temperature fluctuations and cold spots
- Acoustic performance – reducing noise transmission through the building envelope
- Durability – protecting the structure from moisture and uncontrolled airflow
In well-designed buildings, improving airtightness is often one of the most cost-effective ways to enhance energy efficiency and occupant comfort.
Is Some Air Leakage Necessary?
While reducing uncontrolled air leakage is important, it is not the goal to eliminate airflow entirely. Buildings still require ventilation to manage indoor air quality, humidity, and pollutant levels.
The key distinction is between uncontrolled leaks, which can’t be managed or filtered, and intentional ventilation, which is designed and regulated.
In energy-efficient or airtight buildings, fresh air is typically introduced through mechanical ventilation systems, such as:
- Heat Recovery Ventilation (HRV)
- Energy Recovery Ventilation (ERV)
These systems ensure adequate fresh air while conserving energy by capturing heat from exhaust air. Blower door testing helps ensure the building envelope is sealed tightly enough to support these systems, improving overall control and performance.
What to Expect During the Testing Process
Our residential blower door testing service is designed to fit within your project timeline and support your specific performance goals. A typical process includes the following steps:
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1. Initial consultation
We review your project type, size, certification goals, and construction stage. This helps us determine the best time to test and what level of performance you’re aiming to achieve. -
2. Equipment setup
A blower door system is installed in a suitable external opening, usually a doorway. All external doors and windows are closed, while internal doors are opened to allow even pressure throughout the building.
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3. Test procedure
The fan creates a pressure difference of 50 Pascals (Pa) between the inside and outside of the building. Sensors measure the air volume required to maintain this difference, revealing the rate of leakage. -
4. Leak detection
Using smoke puffers, a Thermo-anemometer, thermal imaging cameras, or hand inspection, we can identify specific areas of leakage. This is particularly helpful during the construction phase or just before final lining is completed. -
5. Reporting
We provide a detailed report outlining your building’s ACH50 or leakage rate, how this compares to relevant standards, and any areas for improvement.
If required, we can conduct follow-up testing after sealing adjustments are made.
Positive and Negative Pressure Room Testing
In addition to whole-building blower door testing, we can also carry out positive and negative pressure room testing.
This is used to confirm that individual rooms or zones can maintain their designed pressure differential at the required airflow rate.
Testing supports the correct operation of HVAC systems, helps verify that equipment is properly sized, and assists with the final commissioning process.
Blower Door Testing Standards: ATTMA & AIVAA Compliance
Green Choice Consulting follows industry-recognised procedures to ensure every test is accurate, repeatable, and suitable for compliance or certification purposes.
ATTMA – Air Tightness Testing and Measurement Association
ATTMA is an internationally respected organisation that sets the technical standards for air leakage testing, including equipment calibration, test setup, and reporting formats.
It aligns with ISO 9972, the global standard for measuring building airtightness.
AIVAA – Air Infiltration and Ventilation Assessment Association
AIVAA is a national body supporting blower door testing in Australia. It works closely with ATTMA to maintain quality assurance in the industry and provides accreditation for professionals working in this space.
All blower door tests conducted by Green Choice Consulting are aligned with ATTMA and AIVAA protocols, providing you with reliable data that meets the expectations of certifiers, regulatory authorities, and energy performance frameworks.
Contact Green Choice Consulting
Get in touch today and learn how we can help ensure your project is compliant with energy efficiency requirements.
Who Uses Blower Door Testing?
- New residential builds aiming for energy efficiency
- Passive House and low-energy homes requiring verified airtightness
- Renovation projects where building envelope improvements are being made
- Green Star or NatHERS projects seeking improved thermal performance or certification evidence
- Commercial developments looking to comply with NCC Section J airtightness provisions
When to Conduct Blower Door Testing
Blower door testing is most effective when carried out before internal linings are fully installed. This allows any detected air leaks to be sealed without needing to dismantle finished surfaces.
For new builds, testing is often scheduled once the external envelope is complete but before plasterboard or internal cladding is installed.
In projects requiring verification (such as for Passive House or Green Star), final testing can also be conducted after construction to confirm airtightness targets have been met.
We’re happy to advise on timing based on your specific build stage and goals.
Blower Door Testing Costs
The cost of blower door testing varies depending various factors, including:
- The size and design complexity of the building
- The location of the site
- Whether the service includes leak detection or follow-up testing
At Green Choice Consulting, we provide project-specific pricing after understanding the scope of your build, whether it’s a single test for a small dwelling or multiple tests as part of a certification process.
To receive a detailed quote, please contact us with your building plans or project information.
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Our Service Area: Perth and Surrounds
We provide blower door testing throughout the Perth metropolitan and surrounding area, including:
- Fremantle
- Joondalup
- Midland
- Rockingham
- Mandurah
- Ellenbrook
- Canning Vale
- Armadale
- Wellard
- Butler
- Kelmscott
- Mundaring
- Kalamunda
- Thornlie
- Cannington
- Other suburbs by arrangement
If your project is located outside these areas, please get in touch – we may still be able to assist or recommend a suitable partner.
Why Choose Green Choice Consulting?
Green Choice Consulting provides residential blower door testing as part of a broader energy assessment and compliance service for clients across Perth. We bring together technical knowledge, practical experience, and a commitment to quality to support sustainable, high-performance buildings.
What sets us apart:
- Perth-based team with local knowledge and national accreditation
- Experience working on projects with NatHERS, Passive House, and Green Star targets
- Reports that are clearly written, standards-aligned, and easy to interpret
- Flexibility to test during or after construction, depending on your timeline
- Capability to support other services, including thermal modelling and energy efficiency consulting
We take a clear, collaborative approach, whether you’re testing to meet compliance, improve design outcomes, or simply understand how your building is performing.
Ready to get started?
Contact Green Choice Consulting on 1300 864 944 to discuss your blower door testing requirements.
Contact Green Choice Consulting
Contact Green Choice Consulting today to discuss your project or arrange a test.
Frequently Asked Questions
Can blower door testing improve my NatHERS or Green Star outcome?
Yes. Reducing air leakage can positively influence your thermal performance or energy model and support documentation requirements for energy efficiency certification.
What if my building doesn’t meet the target?
We’ll help you identify where air is escaping and recommend targeted sealing improvements. We can then retest to confirm any improvements.
Is blower door testing suitable for commercial buildings?
Yes. It is commonly used in offices, schools, retail spaces, and healthcare facilities to demonstrate compliance with Section J or achieve Green Star points.
What’s the difference between ACH and m³/h in blower door testing?
- ACH (Air Changes per Hour) refers to how many times the total air volume in a building is replaced in an hour under test conditions.
- m³/h (cubic metres per hour) is a direct measure of the total airflow required to maintain a pressure difference.
Both are used to assess airtightness, with ACH more common in residential settings and m³/h or m³/hr/m² often used in commercial or Green Star contexts.
Will blower door testing damage the building or systems inside?
No. Blower door testing is non-destructive. The pressure used during the test (typically 50 Pascals) is well within the structural tolerance of buildings and doesn’t cause damage to finishes, fixtures, or HVAC systems.
Testing is performed with care to ensure the integrity of the building is maintained.
Can blower door testing help identify specific problem areas?
Yes. In addition to measuring overall airtightness, the process can include leak detection using smoke, thermal imaging, or physical inspection.
This allows builders or contractors to locate and seal problematic gaps, penetrations, or weak points in the building envelope.
Do I need to prepare the building before the test?
Yes, the building needs to be in a suitable state for testing. This generally means that doors and windows are installed, external penetrations are sealed, and construction is at a stage where the building envelope is mostly complete.
We’ll can advise on this prior to testing to ensure the building is ready on the day of the test.
Arrange Your Blower Door Test in Perth
Whether you’re aiming to improve energy efficiency, meet compliance requirements, or certify a high-performance building, blower door testing is a reliable and practical step.
Contact Green Choice Consulting today on 1300 864 944 or fill out our enquiry form to discuss your project or arrange a test.