More of a wwyd....smoking weed

[Spaghettihead1]

Next door has had a young relative living with them for the last few years. He's a skunk smoker.

Im not against this, or what people do in their own homes, but the smell drifts through the wallls into our house.
It's strongest in the attic (I assume he has the attic bedroom next door) and, depending on the amount he's smoking, we can sometimes smell it in the rest of our house.
I've never really been too bothered about it, but I'm thinking I'm going to have to approach him about it soon because our 4 year old will be moving up into the attic bedroom in a few months.
I have no idea if any effects will be coming through the walls to, but I certainly don't like the idea of a 4 year old being exposed to the smell of a drug. He made a remark about it stinking in there when he came up as I was de cluttering the other day.
Wwwyd?
How would you approach the subject?

You can't be ok with it and then object to it when it affects your child. It's a drug, it's not ok.

I'd politely ask the relative to smoke outdoors.

Just go round and talk to the lad. Explain as you have done here. Say you're not against him smoking generally, it's about the smell in the attic. He may well be able to smoke somewhere else in the house. From my experience of young men, they're often protective of little children and you may be pleasantly surprised.

Could you chat to the boy himself - explaining that you don't care if he smokes but that you don't want your LO exposed to it? Maybe suggest that he goes round the other side of the house? I suppose this depends on how well you know him/your neighbours. Good luck.

You can't be ok with it and then object to it when it affects your child.

Why not? A libertarian would see it as a personal choice, but concerned when a child is exposed to 2nd hand smoke. Seems fairly reasonable to me.

tell him the attic stinks of weed and youve put up with it for a while, but you need to use the room soon and its actually a big issue.

If you can smell it that strongly through your house, id probably assume he was growing it and drying it there

Thanks all.
He's a nice lad so I don't think they'll be much of a problem, it's just how to say it. And he's probably very unaware that it comes through the walls - solid stone 120 year old terrace.
I don't think he's growing it. In my teens a boyfriend used to smoke it and I'd be able to smell it at the open front door when it was in his attic room wrapped in foil and untouched. It's so potent!