This just in from 'facebook' sources - (hope I'm posting it in the right section!)
"If your spare bedroom is 70 square feet or under, it is classed as a BOXROOM. It therefore cannot be charged bedroom tax, as listed under the Housing Act 1985. This was put to the Council today and proven to be right. Please measure your room and put your foot down - 9' x 7' = 63 square feet!!"
I have no idea whether this is right or not - just putting it out there for those affected to consider/research (we don't have a spare room ourselves...)
- niemanda (Jay) x