Two classroom "clusters" were tested. Unfortunately, the main contractor did not prepare these areas for testing, ie did not seal around ducts, penetrations, sockets etc. This made the testing rather pointless. Nevertheless, the second tested cluster was sealed after a bit of a discussion. The results were: 6.5 for the "untouched" cluster and 4.3 for the "sealed" cluster. The 4.3 figure equated to approx 0.14m2 of free area over two 65m2 classrooms. The smoke test was carried out around windows - these generally performed well, apart from large sliding doors. No formal report was issued, as the results were not entirely "validated".
The engineer from Stroma advised that it would have been more useful for them to carry out an audit before any testing, to highlight any potential leakage areas and advise on sealing using appropriate products. We will do this prior to final testing in spring.
Nick - you've won the bet.