Thanks Kush Over. First off ventilation isnt a problem... there is easialy a few 1000 sqr. ft. in this attic LOL. Im more afraid of the temps when i get into flowering and the lights are off... hopefully by then the weather will be warmer.

As for smell, there is a basically a direct hole from the attic outside at the top of the roof... my question is at the maximum amount of smell from 10-12 plants would it be noticable outside? (considering that the fumes would be reaching the outside air at the height of a house)