Alcohol is by far a worse drug than Cannabis. It's just, for some bizarre reason, seen as more socially acceptable. Give it a while and the UK will catch up to the rest of the world.
What I find really weird is when I tell people I don't really drink unless I am having a meal. They quiz me to work out why I'm the one who doesn't drink to excess as if I'm the weird one for not wanting to literally swallow a poison.
OP - You'll find most smokers will be more than reasonable. I'd say either a little friendly knock on the door or maybe a letter explaining you can smell it in your property and would appreciate if they could mask the smell more. No need to get the police involved and knocking on their door.
Now, if they're low-lives who have no respect for anyone but themselves and you've tried to be civil. Then I presume you'd have nothing left to try but call the police.
