It’s not commercial, so can they claim housing costs?

Recently attended a Housing Benefit appeal on commerciality/liability etc, which was unsuccessful.  This was no great surprise on the facts of the case.

The thought then popped in that they might be able to claim housing costs instead, on the basis that someone else is liable to pay the mortgage on the property, but is not doing so (the landlord/brother of the claimant).

Seems to rest on whether it is reasonable for the claimant to pay instead.

I think I can predict the DWP response, but has anyone got any experience of trying this?

I’ve managed to persuade them a couple of times that I can remember off the top of my head (though as far as I recall, in both cases the client was the (abandoned) ex partner of the person technically liable to pay the mortgage). Worth a go anyway I would think?