0.4 air changes per hour!!

Our airtightness test went really well yesterday. The team achieved a fantastic result of just around 0.4 a.c.h., probably a bit lower, based on an internal ventilation volume of 400m3 - all the more impressive as this is the first build of this type they had worked on, and because more than half of the build is retrofitting the original structure.

We should be able to improve on that figure in the final test needed for Certification, as we were able to identify the relative weak points.

We spent a little time today working out how much extra time we spent into doing tasks that were necessary to achieve it. Our conclusion was that it was not a significant extra task. However, everyone in our team are really committed to paying attention to protecting the airtightness layer. We have not had to have a formal "Airtightness Champion" trying to watch everyone constantly, in case it was damaged.

Watch a clip of the airtightness test on YouTube: http://www.youtube.com/watch?v=nMTLfj4iXec