I think I disagree that you have two decisions. As I see it, there is one decision in this case, which is to make an award of HB of a certain amount from a certain date. All the bits and pieces that go into the making of that decision are not themselves decisions in the sense meant in the regulations. (If you look at the schedule about decision notices in the regs it clearly describes a decision notice as notifying [u:0a74b5b039]one[/u:0a74b5b039] decision, which could never be the case under the interpretation given in the post above).
In particular, if you look at paragraph 6(2)(c) of Schedule 7, it specifically restricts an appeal against “[u:0a74b5b039]so much of[/u:0a74b5b039] any decision… as adopts a decision of a rent officer”. Hence, a ROD is only part of an LA’s decision as to someone’s entitlement, not a separate decision in itself. A person can appeal against that decision, but if their grounds of appeal relate only to the ROD then the appeal is OOJ.
Therefore, in my view, by making the award of HB for a longer period than previously you have revised the original decision in their favour and therefore lapsed the appeal. They now have fresh appeal rights against your new decision.
By the way, our approach here is to treat an “appeal” which is blatantly purely against a ROD as a request for a redetermination of that ROD and to treat it accordingly.