Main residence/second home question.

I work away, I havent worked since the beginning of the Christmas break, but am now going back to work in the next week or so. My question is, I will be renting digs, but now my home in Scotland will be empty. I will return home (to Scotland) for a maximum of 3 nights a month. Can I, and is it beneficial to me, to class this as a second home? Tax mainly, council tax etc.

My main residence, is likely to be a caravan, or a room share, so will be "all in" bills, IE no council tax paid directly by me.

Any ideas please?