Airtightness Assessment of Commercial buildings
Providing Build Airtight consultancy and Blower Door testing services to the Melbourne area, Geelong Area, Mornington Peninsula and Victoria. 
What We Do
We help clients achieve greater energy efficiency and occupant comfort levels by identifying air leakage issues in their premises enabling informed remedial action to ‘make the building tight and ventilate it right’. We do this in 3 key ways:
  • Advisory prior/during design & construction to advise or offer direction in achieving an airtight building.
  • Airtightness testing during construction phase of your new building or during a refurbishment – to verify the airtightness target of the design is being met/exceeded.
  • Diagnostics - should the airtightness target not be met we can perform detailed diagnostics utilising physical inspection, tracer smoke and thermal imaging technology, to produce a report, highlighting remedial actions for your builder.
blower door test, fan door, air permeability, air pressure testing, thermal imaging, thermography, condition monitoring

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Better funding terms may be available to you for undertaking works which will improve your building's performance in terms of energy, water or waste.

An initiative from the:

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Sealing of penetrations

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Blower door set-up

Inside view - a thermal image of an external house door.
Air leakage into the building is seen as darker colours at architrave.
Airtightness - Benefits of improving the building:
  • HVAC Optimisation - By measuring building air leakage, identifying and then rectifying issues, you will reduce your; heating/cooling losses, system load, energy usage, and running costs.
  • Identify contributors of heating, cooling and comfort issues which can be remedied to improve occupant comfort, potentially increasing productivity and staff wellbeing.
  • Increase the value and attractiveness of the property/development to future investors.
  • Gain insight into the level of quality to which your building has been built.
  • Quantify how "leaky" your building is for comparison to benchmarks.
  • Better building airtightness leads to better rejection of outdoor noise, and helps make the building "feel" better to be in.
  • Increase the green credentials of the property by improving its energy conservation and reduced environmental impact.
  • Potentially gain "Green Star' points from the Green Building Council of Australia.

The GBCA is leading the way in giving prominence to Building Airtightness as an essential element in achieving a Sustainable Built Environment.

Greenstar points are available for projects in relation to having an Airtightness test performed, and for achieving good results.


  • Prior/during design to advise or offer direction in your approach to achieving an airtight building.
  • Conduct an on-site briefing on how to build airtight with Builder and Site Manager who in turn can brief the trades people used.
  • Inspection to check air sealing is being performed through the construction stages.

Airtightness/ Blower Door Test

  • Gaps are often obscured by internal building finishes or external cladding. The only satisfactory way to verify that the building fabric is reasonably airtight is to measure the leakiness of the building fabric as a whole.

  • We do this by performing a Fan Door (aka Blower door) air pressure test of the building. The fan creates pressure differentials between the internal and outside environment, and allows measurement of air leakage over a range of pressures to return an air leakage result which is reported in ACH (air changes/hour) and/or m3/hr.m2 (air permeability rate).


  • If the test result does not meet the client's target, we can locate where air leakage is occurring.

  • With the blower door running we use diagnostic tools such as an infrared camera and tracer smoke to locate the main leakage areas. The images and recorded data is compiled in an audit report which provides the customer/builder with specific areas for sealing/remediation.


3ARK Brochure of Airtightness services.

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3ARK House Airtightness Services

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Life cycle for delivering an Airtight Home

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3ARK, helping people to reduce energy costs.

Fan door

Three fans set up for air leakage testing.

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Retrotec Trained lead testers.
Certified to Level 1, 2 and 3 (large/complex buildings) in the use of Fan Door for Air Leakage Testing in Large Buildings..
Door leaks

ABOVE - Outside view of heated air escaping at the top of the door jam and cold air getting drawn in at the bottom.

ABOVE - Air Leakage through gaps between the window architrave and plasterboard wall.
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ABOVE - a wall mounted Air Conditioner.
Air leakage is evident behind the unit at the lower left where its refrigeration piping passes through the plaster wall.

ABOVE - IR image of a floor heating vent and window.
The darker areas show the outside cool air that is leaking into a room - at the skirting boards, window sills and surrounds, around the floor vent,..

ABOVE - Missing insulation along the edge of the ceiling.
ABOVE - Suspicious thermal pattern on a plaster ceiling.
The thermal pattern is consistent with the presence of moisture, Further investigations revealed that new roof sheeting had leakage issues after a severe storm.
ABOVE - A regular photograph of the plaster ceiling in the accompanying IR image at the left.
No initial indications of any issues, however that would most likely change as the water soaks through and affects the plaster, as well as possibly enabling mould growth.