tristaleejac, not meaning to hijack your thread, but if it helps here is my experience..
dp smoked when i met him -we moved in together a few years ago and i also smoked now and again (have never bought it, but have shared with other people).
about six months after we moved in i started to get sick of the smell and we agreed he would limit it to one room, it still stank the place out though.
i got pregnant last february and was actually horrified when he lit a joint in our living room after i had broken the news and we had decided to keep the baby.
to cut a long story short, the issue of not smoking in the house turned into a perpetual battle for the length of my pregnancy which was not only unhealthy, but really damaged our relationship. what sort of person would argue about compromising on something like that for the sake of a child? it was so tiring and extremely depressing that we couldn't reach a common ground about it, and that he persistently chose that over us.
DD is now here and nine months old. He finally stopped smoking altogether when she was about five months old. The first five months of her life were spent arriving at the realisation that he actually had a serious dependency on cannabis, and becoming aware of the psychological damage he has suffered as a result of smoking it (in what I felt was moderation) for so long.
He totally withdrew from DD during this time, and isolated me at home to try and force concession on my part (he didn't get it), but he actually behaved so disgustingly -sulks, tempers, days of silence and ignoring me- that i felt in serious danger of having some sort of nervous breakdown. I was recovering from dd's fairly dramatic delivery and it felt like he just abandoned me -worse, in fact, it felt like he persecuted me exactly when i really really needed his support.
I don't know at this point whether 'we' will survive as i still feel totally and utterly betrayed by him and don't know if I will ever actually forgive him or trust him again.
I would really recommend you are absolutely sure he isn't addicted and that you have reached a mutually agreeable arrangement about him not smoking in the house before you move your kids in with him. I'm actually guilt ridden about some of what my DD has witnessed as a result of our clashes over this issue.