The relevant CN in the technical manual, which confirms that no concessions are given to the criteria, reads:
‘Where national building regulations limit the use of recycled aggregates in concrete (typically applicable to bound aggregate uses as listed), the onus for achieving this credit is on the unbound uses (please note that the total aggregate figure must still include the bound uses).’
To clarify, in the calculation, the percentage of recycled aggregates in both bound and unbound uses can be considered against the total high grade use for the project.
Technical manual to be updated accordingly in next reissue.