I’m more of the opinion that whilst not in HA property they shouldn’t be charged rent than before following your reply. Perhaps it would reflect badly as a “void” property on the part of the HA and they’re trying to avoid that – obviously don’t know enough about your particular case to comment further on that.
Other thought is – did the HA arrange the temporary accommodation with your homeless section or are they picking up the tab for it, in which case it would, to my mind be a decant and the rent being charged on the original home would be seen to cover this (thinking as I type and that, believe me, is dangerous!!)
If they aren’t being charged for the temporary property then there isn’t a liability on that property to worry about and I would go along with Reg 7(4) and treat as though liable for property undergoing restoration.
Maybe simplistic, but, problem solved?
Do I know what I'm doing? The jury's out on that........................