to not want BIL here...

[hondagirl500]

Long story short - BIL is an alcoholic. Lives in a caravan a few miles away, does odd jobs for people, cash in hand. The owner of the land where the caravan is, has told BIL he needs to leave, he is getting rid of the van - tomorrow!
BIL has nowhere to go, and no money for rent etc.
He will be homeless.

We live in a small, 3 bed house, all kids have grown up and left home so we have a spare room. I do not want an alcoholic in my house. So far, DH has not suggested he comes here....but WIBU to refuse to have him here?

Not at all. Let the useless old soak live with the consequences of his appalling choices.

What an utterly vile comment. If it’s such a rotten life do you think someone chooses it or do you think perhaps they may be trapped into a dependency influenced by factors you know nothing about. Have some compassion for another human being.

But no, OP, that doesn’t mean you need to have him to live with you. It really depends on your relationship and history as to whether you could offer advice but firmly no accommodation, or a strict two weeks with conditions attached while he seeks social care help. I think it would be kind to try and give some assistance but you’re not obliged to take someone into your home and it really depends on your history with BIL.

I agree with previous pps. He needs to hit rock bottom to want help. It's sad, but that's how it is.
I think your DH doesn't want him there either since he hasn't asked.

I would give him a bed for a limited time.

How would you make sure it was "for a limited time" though?
Unless OP's BIL is genuinely committed to addressing his alcoholism his prospects of finding a secure tenancy are pretty slim. It will be easier for OP not to offer him accomodation in the first place than it would be to get him to leave once he's got his feet under the table. Sure, she could say "just til you find something else" but is he going to he motivated to look once he's installed in a nice, comfortable home? Yes, she could give him a specific date he has to be out by, but then what is she supposed to do if he doesn't leave at the agreed time?
Sadly, I come from a family of alcoholics and my job also frequently brings me into contact with problem drinkers. In my experience, people who have a problem with alcohol often find it very difficult to stick to their end of a deal. They will say all the right things, possibly with genuine intent to do the right things, but it rarely translates into action. When it comes time to do what they've sworn blind they're going to do there will be delays, endless excuses, avoidance, manipulation or even aggression. It's all very well telling OP to do the kind thing but if she opens her door to someone with an addiction she needs to know what she could be letting herself in for.

Don't let him across the threshold. He needs to be in a desperate enough situation for the council and other services to help him. They'll do nothing if you give him even one night. Stop making phone calls for him too. Even that is enabling him to avoid responsbility for his own life. He is an adult, he can use google and phones. If he chooses not to, it's exactly that, a choice he has made. Back right away until he, by his own choice and actions, gets sober.