Ms Orla Hegarty:

I do not think we can know without assessing them. However, the regulations we have are very generalised for natural ventilation. Even design performance may not reflect the actual performance. How they perform on paper may not be what happens in reality. What happens this morning may be compliant, but with a change of wind direction, a very still day, somebody not opening a window or somebody blocking a vent this afternoon, it could become very non-compliant. It is impossible to say where the problem is.

As we also have a system of self-certification, it is impossible to know who signed off on that building and whether they did a careful assessment, whether they gave good advice to the people who are running the building or whether a subsequent change was made without any professional input, for example, changing doors, adding partitions, doubling up on rooms or something else.