What do you think of run-in-sheds?

I know they need to be built right and facing the right direction for wind and the elements. Run in sheds need to be spacious with many exits. You want to make sure horses can’t get cornered in them and that there isn’t metal exposed they can cut theirself on… If you do not have natural shelter and you do not plan to put horses in, then run-in sheds or some type of shelter is a must in these northern states.