Blower door testing, also known as airtightness testing or air leakage testing, measures how much uncontrolled air leakage is occurring through a building envelope. It is one of the most effective ways to verify construction quality and understand how a building is likely to perform once occupied.
Performance Building Consultants provides blower door testing in Wānaka, Queenstown and across Otago, Canterbury and Southland, for both residential and commercial buildings.
Why airtightness matters
A building can have excellent insulation and high-performance windows, but if there are significant gaps and leaks in the building envelope, energy and comfort can still be compromised.
Uncontrolled air leakage can contribute to:
- Cold drafts and uncomfortable indoor temperatures
- Increased heating energy use
- Uneven temperatures between rooms
- Reduced effectiveness of insulation
- Moisture transport and condensation risks in some building assemblies
- Difficulty achieving the intended level of building performance
A blower door test provides a measurable result for building airtightness, typically expressed as air changes per hour (ACH). More importantly, it can help identify where air is leaking so that problems can be fixed.
Find and fix air leaks before handover
Blower door testing is most valuable when it is carried out before a building is fully finished, when air leaks can still be located and repaired relatively easily.
The test uses a calibrated fan installed in an external doorway to create a pressure difference between the inside and outside of the building. This allows the overall air leakage of the building to be measured, while diagnostic techniques can be used to help locate leakage paths.
Testing can therefore provide builders and design teams with an opportunity to identify and rectify air leakage before handover, rather than discovering problems after the building is occupied.
For existing buildings, airtightness testing can also help identify leakage paths during renovations or energy-efficiency upgrades.
Blower door testing for high-performance buildings
Airtightness is particularly important for high-performance homes, Passive House projects and energy-efficient buildings, where the building envelope is designed to minimise uncontrolled heat loss and improve comfort.
Testing can also be used to verify performance for projects targeting Homestar and Green Star, where measured building performance can contribute to project outcomes.
Certified ATTMA Level 2 testing
I am an ATTMA Level 2 certified airtightness tester, qualified to carry out blower door testing on residential buildings as well as larger commercial buildings.
This includes multi-zone buildings and projects requiring multiple fan systems, making the service suitable for everything from individual homes through to larger commercial developments.
Blower door testing in Wānaka, Queenstown and beyond
Blower door testing is suitable for:
- New residential builds
- High-performance homes
- Passive House projects
- Commercial buildings
- Renovations and energy-efficiency upgrades
- Buildings targeting Homestar or Green Star outcomes
Whether you need to verify the airtightness of a new home, identify air leakage before handover, or demonstrate the performance of a high-performance building, blower door testing provides measurable evidence of how well the building envelope is performing.