Diminishing notional capital when rental liability split

May be lacking in research skills but can’t find an answer to this.

Client was assessed as having about £25k in notional capital (deliberate deprivation). She has separated from her ex-husband but they still share a house. She was previously the lead claimant for HB. When the notional capital decision was made he put in a claim for HB and receives 50% of the rent, she pays the remainder from her PIP.

When assessing the diminishing notional capital should 100% of the HB/CTR be used or just the 50% that she is now liable for?