New grow set-up

I forgot intake, just intake through your house, no need for an outside intake, just use your climate controlled air from your house to keep things consistant.
this will raise your heating bill a bit, but you won't really notice i don't think.
Also i think you should wait on the Co2, intake through the home will bump co2 levels and you should have some grows under your belt and a baseline of your results to see if co2 will actually benefit you, its best in sealed situations and with 4-5 kw you cant seal without a big a/c unit.

I think leave the veg, i can help u light proof it easy peezy. and the ventilation would work best that way.

Actually did move my veg I can't imagine having to go through in the dark to get there I spend so much time in my veg right now. But to update, had a small issue with powdery mildew. Knocked it down, managed to save a few clones and with the help of a friend have another 10 clones in an aero right now. My friend also had a couple girls pretty close to flower so gonna put 1 light up in the flower room with them and use the vent setup u recommended. Co2 will be later but I think that setup will be easy, just expensive to do safely which I won't comprimise on with the wife and dog .

LoL yeah i guess that would be a pain in the ass, i really missed that in the drawing, but i imagine you remembered it every time you went in there. Glad to hear things are going well, let me know if you need anything.