I am under occupying my house (its what I was housed in when I needed a home) as its a 3 bed and its just me and ds. I'm well aware of the changes to benefits because of this, and have looked at down sizing (i would find a swap v.easily) but I physically couldn't afford to do it if I wanted to.
I don't know if its different with other councils but ours off no support, yet to move it will cost you a huge amount- removals, changing of details for everything, bills etc, reflooring (in some cases- many I have seen have no flooring and I've spent ££££ on this house, flooring, repairing and decorating) etc. Surely if they need the houses enough then they're going to have to aid those moving?