Cavity wall insulation and sub floor ventilation

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My property has a suspended timber floor and was extended at the entier rear part of the old house  with a solid concrete floor. We have been told by RICS surveyor that the airflow was already inadequate with only 3 aibricks for the whole of the subfloor and it seems as if this should have been flagged up during the pre install survey.
In fact we got a CIGA authorised remediation contractor to review the property for extraction and re-install and he said that it wasn’t suitable for reinstall but regardless we needed 4 new air bricks to meet the current regulations.

According to Technical Note 18
"Extensions built to extend across the entire rear elevation of a property also compromises this essential cross flow ventilation, raising humidity below the timber floor and increasing the potential risk of timber destroying mould growth to develop.
CIGA has seen a marked increase in recent years of timber floor board and joist deterioration caused by reduced cross flow ventilation, with total collapse in some instances within two or three years of the installation of cavity wall insulation."
CIGA Technical Note 18


What did CIGA inspector find?

This was clearly negligence on behalf of the installer.The fully trained inspector should have followed CIGA's technical notes though?
It seems not. There was no mention of the airbricks at all not number, size or patency.
The only reference to the floor was 
"Ground floor construction is suspended timber joist with timber floor boards."
Which is clearly incorrect. Again Nigel Donohue the CEO of CIGA stands by this report as being accurate but it is objectivey is not.
I will be pulling up the floor boards to check all the joists next week to check the integrity of the joists. 

This is not a small issue at all. Here are some examples where where the ventilation path has been inadequate reulting in joist failure.


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