High-performance buildings have more design and construction thought put into them than a typical New Zealand project. As discussed in one of our other articles, the designers and builders are trying to minimise the thermal losses from the project. This inherently means that the buildings become more air-tight with less or no thermal-bridging in the construction. So, the obvious questions arise, if we have spent all of this time and energy designing and constructing a high-performance home, how do we verify we are getting what we asked for?
The simple answer is to carry out a blower door test. This is an internationally recognised testing system that provides tangible results for the project team to use during the build. The blower door is fitted to a doorway or window opening in the building. It then pulls air into the building and monitors the amount of air that leaks or is lost out of the building envelope. It then provides a test result that is universal throughout the world and allows the owners to benchmark their project. There isn’t a better way to see where parts of the building may not have been built as well as others then using smoke inside the project and seeing it pour out of the home. It is a clear and simple tool for any high-performance building team.
We recommend that the blower door is used at two times during construction. The first time is before the project is lined, this is when issues can be amended and lessons learnt. The second is when the home is complete, this provides a final performance measurement for the owners to either use to assist in officially certifying their Passihaus, or knowing where their home is on the performance ladder.
TAWA has performed many blower door tests on client’s homes, and sometimes once the project has been completed to verify results. Once the home is completed there really is no way to amend the building envelope to increase its performance. So, we suggest you consider this approach early in your design phases.
We encourage you to get out there and start having conversations about blower door testing. If this is something you are interested in, give us a call or if you are not in the Waikato or the Bay of Plenty go to www.blower-door.co.nz to find a local blower door expert in your area. The test is completed within an hour, so we suggest you start the conversation with your build team for your next project and demand to know what you are paying for in terms of performance.
